M3-Brigade Acquisition V Corp.

FOR AN EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS OF THE COMPANY

To be held at 11 a.m. Eastern Time on July 17, 2026

The information provided in the Questions and Answers below are only summaries of the matters they discuss. They do not contain all of the information that may be important to you. You should read carefully the entire document, including the annexes to this proxy statement.

Questions and Answers

About the Extraordinary GENERAL Meeting of Shareholders

Why am I receiving this proxy statement?

This proxy statement of M3-Brigade Acquisition V Corp. (the “Company,” “our,” “we” or “us”) and the enclosed proxy card are being sent to you in connection with the solicitation of proxies by our board of directors (the “Board”) for use at an extraordinary general meeting of shareholders of the Company (the “Meeting”), or at any adjournments or postponements thereof. This proxy statement summarizes the information that you need to make an informed decision on the proposals to be considered at the Meeting.

We are a blank check company incorporated on March 12, 2024 as a Cayman Islands exempted company and formed for the purpose of effecting a merger, share exchange, capital stock exchange, asset acquisition, share purchase, reorganization or similar business combination, involving the Company and one or more businesses (a “business combination”). Our sponsor is MI7 Sponsor, LLC, a Delaware limited liability company (the “Sponsor”).

On August 2, 2024, the Company consummated its initial public offering (“IPO”) of 28,750,000 units (the “Units”), with each unit consisting of one Class A ordinary share, par value $0.0001 per share (the “Class A Ordinary Shares”), and one half of one redeemable warrant (the “Public Warrants”) of the Company, with each whole Public Warrant entitling the holder to purchase one Class A Ordinary Share for $11.50 per share, subject to adjustment, which included the full exercise by the underwriters of their over-allotment option in the amount of 3,750,000 Units, at $10.00 per Unit, generating gross proceeds of $287,500,000. Simultaneously with the closing of the IPO, the Company consummated the sale of 8,337,500 warrants (the “Private Placement Warrants”). Following the closing of the IPO, on August 2, 2024, an amount of $288,937,500 ($10.05 per Unit) from the net proceeds of the sale of the Units and the sale of the Private Placement Warrants was placed in the trust account administered by Continental Stock Transfer & Trust Company (“Continental”), acting as Trustee (the “Trust Account”).

Like most blank check companies’ governing documents, our amended and restated memorandum and articles of association (the “Articles”) provide for the return of the IPO proceeds held in trust to the holders of publicly-held Class A Ordinary Shares (“Public Shares”) if there is no qualifying business combination consummated on or before a certain date. In our case, such certain date is August 2, 2026 (i.e., upon the expiration of the 24-month period following the consummation of the IPO, which period we refer to as the “business combination period”). If the Extension Proposal (as defined below) is approved, the business combination period will instead be extended until August 2, 2027 (i.e. within 36 months from the consummation of its IPO) or such earlier date as may be determined by the Board in its sole discretion. Our Board believes that it is in the best interests of the Company and its shareholders to extend the business combination period until that date. Therefore, the Board is submitting the proposals described in this proxy statement for the shareholders to vote upon.

As of the date of this proxy statement, the Sponsor, who we expect to vote in favor of the Extension Proposal, and shareholders who entered into Voting and Non-Redemption Agreements and Voting Agreements beneficially owned approximately 74% of the outstanding Ordinary Shares. Accordingly, unless the Sponsor does not vote in favor of the Amendment Proposals, or the Voting and Non-Redemption Agreements and Voting Agreements are terminated in accordance with their terms, the Amendment Proposals will be approved without the need for the affirmative votes of any other shareholders.

Only holders of record of our Class A Ordinary Shares and Class B Ordinary Shares of the Company, par value $0.0001 per share (the “Class B Ordinary Shares,” and, collectively with the Class A Ordinary Shares, the “Ordinary Shares”) at the close of business on June 25, 2026 (the “Record Date”), are entitled to notice of the Meeting and to vote at the Meeting and any adjournments or postponements of the Meeting. All Class B Ordinary Shares in the share capital of the Company are currently held by our Sponsor. If you are receiving this proxy, the Company has identified you as a holder of Class A Ordinary Shares as of the Record Date.

What is being voted on?

You are being asked to vote on the following proposals:

1. Proposal No. 1 — The Extension Proposal — A proposal to approve, by way of special resolution, an amendment to the Company’s Articles in the form set forth in Annex A, to extend the date by which the Company must consummate an initial business combination by 12 months (the “Extension”) (to August 2, 2027, or such earlier date as may be determined by the Board in its sole discretion (the “Extension Date,” such amendment to the Company’s Articles the “Extension Amendment” and such proposal, the “Extension Proposal”)) and such other modifications to the Articles as may be necessary to give effect to the Extension Proposal;

2. Proposal No. 2 — The Trust Interest Withdrawal Proposal — A proposal to approve, by way of special resolution, an amendment to the Company’s Articles in the form set forth in Annex A, to permit the Company, following the effective date of this amendment and the redemption of Public Shares in connection with the approval of the Extension Amendment, to withdraw up to an aggregate amount of interest earned on the funds held in the Company’s Trust Account, equal to $0.10 for each outstanding Class A Ordinary Share, held by a public shareholder that is not redeemed and remains outstanding immediately following the effective date of this amendment, of which (a) $1,000,000 will be used to pay certain ordinary course expenses of the Company and (b) any amounts in excess of such $1,000,000 will be used to pay accrued liabilities as of the effective date of the amendment to the Company’s Articles (“Trust Interest Withdrawal Amendment” and such proposal the, “Trust Interest Withdrawal Proposal”) and such other modifications to the Articles as may be necessary to give effect to the Trust Interest Withdrawal Proposal;

3. Proposal No. 3 — The Name Change Proposal — A proposal to approve, by way of special resolution, (i) a change of name of the Company from M3-Brigade Acquisition V Corp. to Velos Acquisition I Corp., and (ii) an amendment to the Company’s Articles, in the form set forth in Annex A, to effect the change of the Company’s legal name (the “Name Change”) to Velos Acquisition I Corp. and to change the definition of the term “Sponsor” to mean MI7 Sponsor, LLC (the “Name Change Amendment” and such proposal, the “Name Change Proposal”), and such other modifications to the Articles as may be necessary to give effect to the Name Change Proposal;

4. Proposal No. 4 — The Fairness Opinion Proposal — A proposal to approve, by way of special resolution, an amendment to the Company’s Articles in the form set forth in Annex A, to remove Article 49.12 (fairness opinion requirement) from the Articles in its entirety (the “Fairness Opinion Amendment” and together with the Extension Amendment, the Trust Interest Withdrawal Amendment and the Fairness Opinion Amendment, collectively, the “Articles Amendments,” and individually, an “Articles Amendment,” and such proposal, the “Fairness Opinion Proposal,” and together with the Extension Proposal, the Trust Interest Withdrawal Proposal, the Name Change Proposal, and the Fairness Opinion Proposal, collectively, the “Articles Amendment Proposals”) and such other modifications to the Articles as may be necessary to give effect to the Fairness Opinion Proposal;

5. Proposal No. 5 — The Trust Agreement Amendment Proposal — A proposal to approve, by way of an ordinary resolution, an amendment, in the form set forth in Annex B, to the Investment Management Trust Agreement dated July 31, 2024 between Continental and the Company (the “Trust Agreement”), to permit the Company, following the effective date of the Trust Interest Withdrawal Amendment, to withdraw up to an aggregate amount of interest earned on the funds held in the Company’s Trust Account in an amount equal to $0.10 for each outstanding Class A Ordinary Share held by a public shareholder that is not redeemed and remains outstanding immediately following the effective date of this amendment, of which (a) $1,000,000 will be used to pay certain ordinary course expenses of the Company and (b) any amounts

in excess of such $1,000,000 will be used to pay accrued liabilities as of the effective date of the Trust Interest Withdrawal Amendment (the “Trust Agreement Amendment,” and such proposal, the “Trust Agreement Amendment Proposal,” and, together with the Articles Amendments the “Amendments” and the Articles Amendment Proposals, collectively with the Trust Agreement Amendment Proposal, the “Amendment Proposals”).

6. Proposal No. 6 — The Adjournment Proposal — A proposal to approve, by way of ordinary resolution, the adjournment of the Meeting to a later date or dates, if necessary or desirable, to permit further solicitation and vote of proxies if, based upon the tabulated vote at the time of the Meeting, there are insufficient votes for, or otherwise in connection with, the approval of any of the Amendment Proposals or if we determine that additional time is necessary to effectuate the Extension or the Amendments (the “Adjournment Proposal”).

Approval of each Articles Amendment Proposal is not conditioned upon approval of any other Articles Amendment Proposal except that (i) the Trust Interest Withdrawal Proposal is conditioned upon shareholder approval of the Extension Proposal and (ii) the Trust Agreement Amendment is conditioned upon shareholder approval of the Trust Interest Withdrawal Proposal. Approval of the Amendment Proposals are a condition to the implementation of the Amendments. The Adjournment Proposal will only be presented at the Meeting if there are not sufficient votes to approve the Amendment Proposals or if we determine that additional time is necessary to effectuate the Extension or the other Amendments.

Does the Board recommend voting for the approval of the proposals?

Yes. After careful consideration of the terms and conditions of the proposals, the Board has determined that the proposals are in the best interests of the Company and its shareholders. The Board unanimously recommends that shareholders vote “FOR” the proposals.

What is the purpose of thep roposals?

The purpose of the proposals being presented to shareholders at the Meeting are to provide us with additional time to complete an initial business combination. As previously disclosed on June 12, 2026, we entered into a Mutual Termination Agreement (the “Termination Agreement”) with ReserveOne, Inc., a Delaware corporation (“ReserveOne”), to terminate the Business Combination Agreement dated July 7, 2025 (the “ReserveOne BCA”) we entered into with ReserveOne, ReserveOne Holdings, Inc., a Delaware corporation (“Pubco”), and certain Pubco subsidiaries (all of the transactions contemplated by the ReserveOne BCA, including the issuances of securities thereunder, the “ReserveOne Business Combination”). The parties entered into the Termination Agreement following careful consideration of current market dynamics and feedback from investors and other stakeholders concerning the ReserveOne Business Combination.

Our Articles currently provide that the Company must liquidate the Trust Account if it has not consummated its initial business combination by August 2, 2026. Without the Extension, we believe that we will not be able to complete an initial business combination on or before August 2, 2026. If that were to occur, the Company would be forced to liquidate. Therefore, the Board has determined that it is in the best interests of the Company and its shareholders to extend the date by which the Company has to consummate an initial business combination to the Extension Date in order for our shareholders to have the opportunity to participate in an investment in a combined company. In addition, the Board believes that it is advantageous for the Board to be able to determine whether to liquidate and dissolve the Company at an earlier date. Approval of the Extension Proposal is a condition to the implementation of the Extension.

The purpose of the Trust Interest Withdrawal Proposal and the Trust Agreement Amendment Proposal is to increase the amount of funds available to the Company to finance expenses in connection with identifying a potential business combination target and consummating a business combination. The Company has incurred significant expenses in connection with the previously announced proposed ReserveOne Business Combination, which terminated on June 12, 2026. The Company will continue to incur expenses to identify an attractive business combination target, including by evaluating potential target businesses, performing business due diligence on potential target businesses, traveling to and from the offices, plants or similar locations of prospective target businesses or their representatives or owners, reviewing corporate documents and material agreements of prospective target businesses and structuring, negotiating and consummating a business combination and other corporate purposes. Deficiencies in working capital may impede the identification of an attractive initial business combination target and the consummation of a business combination.

Accordingly, our Board believes that implementation of the Trust Interest Withdrawal Amendment and the Trust Agreement Amendment is advisable to provide the Company with additional working capital to support the Company’s efforts to identify an attractive business combination target and consummate an initial business combination.

If the Trust Interest Withdrawal Amendment and the Trust Agreement Amendment are implemented, working capital would be permitted to be distributed to the Company from the interest earned on the funds in the Trust Account to the extent such interest is accrued prior to the date of the Trust Interest Withdrawal Amendment. The Trust Agreement Amendment would permit the Company, following the effective date of the Trust Interest Withdrawal Amendment, to withdraw up to an aggregate amount of interest earned on the funds held in the Company’s Trust Account in an amount equal to $0.10 for each Class A Ordinary Share issued in the Company’s initial public offering and held by a Public Shareholder (as defined below) that is not redeemed and remains outstanding immediately following the effective date of the Trust Interest Withdrawal Amendment, of which (a) $1,000,000 will be used to pay certain ordinary course expenses of the Company and (b) any amounts in excess of such $1,000,000 will be used to pay accrued liabilities as of the effective date of the amendment to the Company’s Articles to the extent such interest is accrued prior to the date of the Amendments. As such, the Company could effectively transfer the costs of expenses to its Public Shareholders (as defined below) that do not elect to redeem their Public Shares in connection with the Extension Amendment by withdrawing interest earned in the Trust Account in an amount equal to $0.10 per Class A Ordinary Share held by a Public Shareholder accrued prior to the date of the Trust Interest Withdrawal Amendment for payment of such expenses. The distribution of such interest by the Trustee shall occur as and when directed by the Company following the implementation of the Trust Interest Withdrawal Amendment. Any such amounts will not reduce the amount distributable to Public Shareholders that elect to redeem their Ordinary Shares in connection with approval of the Extension Amendment, but would not be included in any funds paid to our public shareholders in the event of future redemptions by such shareholders or a liquidation of the Company.

The Name Change Proposal is being put forward to change Company’s name from “M3-Brigade Acquisition V Corp.” to “Velos Acquisition I Corp.” and to change the definition of the term “Sponsor” to mean MI7 Sponsor, LLC. The Name Change Proposal is being put forward to reflect the new direction of the Company following the termination of the ReserveOne Business Combination.

Section 49.12 of our Articles requires that in the event we enter into an initial business combination with a target business that is affiliated with our Sponsor, a Founder, a Director or an Officer (each, as defined in the Articles), we, or a committee of our independent directors, must obtain an opinion from an independent investment banking firm or another valuation or appraisal firm that regularly renders fairness opinions on the type of target business the Company is seeking to acquire that is a member of FINRA or an independent accounting firm that such a business combination is fair to the Company from a financial point of view.

The purpose of the Fairness Opinion Proposal is to eliminate the requirement to obtain a fairness opinion with respect to certain potential business combination transactions and provide the Board greater flexibility to determine whether to obtain a fairness opinion with respect to any such potential transaction, including, without limitation, (i) if the Sponsor or management has a material interest in a proposed business combination, (ii) the size of a potential business combination, (iii) the potential target’s industry and whether market price of companies in such industry are volatile, (iv) the cost of a fairness opinion and other transaction expenses for a proposed business combination and (v) whether fairness opinions are typically delivered in similar transactions as the proposed business combination.

The purpose of the Adjournment Proposal is to allow the Company to adjourn the Meeting to a later date or dates if we determine that additional time is necessary to permit further solicitation and vote of proxies in the event that there are insufficient votes to approve the Amendment Proposals or if we determine that additional time is necessary to effectuate the Extension or the other Amendments. The Adjournment Proposal will only be presented at the Meeting if there are not sufficient votes to approve the Amendment Proposals or if we determine that additional time is necessary to effectuate the Extension or the other Articles Amendments.

The Sponsor has agreed to waive its redemption rights with respect to its Founder Shares (as defined below) and Public Shares (as defined below) in connection with a shareholder vote to approve the Articles Amendments.

You are not being asked to vote on any business combination transaction at this time. If the Extension Proposal is implemented and you do not elect to redeem your Public Shares now, you will retain the right to vote for an initial business combination when it is submitted to shareholders and the right to redeem your Public Shares for cash in the event our initial business combination is approved and completed or if the Company has not consummated the initial business combination prior to the Extension Date, subject to the terms of the Articles.

Why should I vote “FOR” thep roposals?

The Board believes shareholders will benefit from the Company consummating a business combination and is proposing the Extension Proposal to extend the date by which the Company must complete a business combination until the Extension Date. The Extension would give the Company the opportunity to complete a business combination, which our Board believes is in the best interests of the shareholders.

The Articles provide that if our shareholders approve an amendment to our Articles that would modify the substance or timing of the Company’s obligation to redeem Public Shares if the Company does not complete a business combination before August 2, 2026, the Company will provide holders of its Public Shares (“Public Shareholders”) with the opportunity to redeem all or a portion of their Public Shares upon such approval (an election for such a redemption, an “Election”). Therefore, in connection with the Extension Proposal, Public Shareholders may elect to redeem their Public Shares (a “Redemption Election”) for a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in the Trust Account (less taxes payable), divided by the number of then outstanding Public Shares, regardless of whether or how such Public Shareholders vote on the proposals at the Meeting. The deadline to make a Redemption Election is 5:00 P.M. Eastern time on July 15, 2026, the date that is two business days prior to the Meeting. However, redemption payments for Redemption Elections in connection with this Meeting will only be made if the Extension Proposal receives the requisite shareholder approval and we determine to implement the Extension.

If any of the Extension Proposal is not approved or implemented, and if the Company does not consummate an initial business combination before August 2, 2026, as contemplated by the prospectus from our IPO and in accordance with our Articles, the Company will (i) cease all operations except for the purpose of winding up, (ii) as promptly as reasonably possible but not more than ten business days thereafter, redeem the Public Shares, at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in Trust Account and not previously released to the Company (which interest shall be less taxes payable and up to $100,000 of interest to pay dissolution expenses), divided by the number of then-outstanding Public Shares, which redemption will completely extinguish Public Shareholders’ rights as shareholders (including the right to receive further liquidation distributions, if any), and (iii) as promptly as reasonably possible following such redemption, subject to the approval of our remaining shareholders and our Board, liquidate and dissolve, subject in each case to our obligations under Cayman Islands law to provide for claims of creditors and the requirements of other applicable law. There will be no redemption rights or liquidating distributions with respect to our warrants, including the Public Warrants, which will expire worthless in the event the Company winds up.

The Board believes it is in the Company’s best interests for the Company to have additional time to complete an initial business combination. The Board is also at liberty to fix an earlier date before August 2, 2027, by which the Company is required to consummate a business combination, and if the Company does not consummate a business combination by such earlier date, the Company shall, subject to the redemption of Public Shares and the approval of the remaining shareholders and directors, be liquidated and dissolved as promptly as reasonably possible.

The Board also believes that it is in Company’s best interests to approve the Trust Interest Withdrawal Amendment and the Trust Agreement Amendment to provide the Company with the ability to withdraw following the effective date of the Trust Interest Withdrawal Amendment up to an aggregate amount of interest earned on the funds held in the Company’s Trust Account in an amount equal to $0.10 for each outstanding Class A Ordinary Share that is held by a Public Shareholder and is not redeemed, of which (a) $1,000,000 will be used to pay certain ordinary course expenses of the Company and (b) any amounts in excess of such $1,000,000 will be used to pay accrued liabilities as of the effective date of the Articles Amendments. Our Board believes that payment of certain accrued liabilities using Trust Account interest if the Trust Interest Withdrawal Proposal and the Trust Agreement Amendment Proposal are approved would make the Company more attractive to potential targets in a business combination by reducing expenses that would otherwise need to be paid at the closing of a business combination and result in less cash to the potential target.

The Board also believes that changing the Company’s name “M3-Brigade Acquisition V Corp.” to “Velos Acquisition I Corp,” will better reflect the new direction of the Company following the termination of the ReserveOne Business Combination.

The Board also has determined that elimination of the fairness opinion from the Articles is in the Company’s best interests. Eliminating the strict requirement to obtain a fairness opinion with respect to certain potential business combination transactions will provide the Board greater flexibility to determine whether to obtain a fairness opinion with respect to any such potential transaction, including, without limitation, (i) if our Sponsor or management has a material interest in a proposed business combination, (ii) the size of a potential business combination, (iii) the potential target’s industry and whether market price of companies in such industry are volatile, (iv) the transaction expenses for a business combination and (v) whether fairness opinions are typically delivered in similar transactions as the proposed business combination.

The Board believes that shareholders should vote for the Adjournment Proposal, because without its approval, if presented, our Board may not be able to adjourn the Meeting to a later date in the event that there are insufficient votes for, or otherwise in connection with, the approval of the Amendment Proposals.

Our Board recommends that you vote in favor of the Amendment Proposals and Adjournment Proposal, but expresses no opinion as to whether you should redeem your Public Shares.

Are any Ordinary Shares already committed to vote in favor of the Articles Amendments and Trust Agreement Amendment?

The Company’s Sponsor is expected to vote all Ordinary Shares over which it has control (including any Public Shares owned by it) in favor of all proposals.

Our Sponsor has entered into a letter agreement with us pursuant to which it has agreed to vote any Ordinary Shares owned by them in favor of any proposed initial business combination and to waive its redemption rights with respect to its Ordinary Shares in connection with (i) the completion of our initial business combination or (ii) a shareholder vote to approve an amendment to our Articles (A) to modify the substance or timing of our obligation to allow redemption in connection with our initial business combination or to redeem 100% of our Public Shares if we do not complete our initial business combination the applicable time frame or (B) with respect to any other provision relating to shareholders’ rights or pre-initial business combination activity. Our Sponsor is not entitled to redeem any of the 7,187,500 Class B Ordinary Shares that it held as of the Record Date.

On June 12, 2026, the Company, the Sponsor, ReserveOne Inc., and ReserveOne Holdings, Inc. entered into Voting Support and Non-Redemption Agreements (the “Voting and Non-Redemption Agreements”) with certain investors (such investors entering the Voting and Non-Redemption Agreements, collectively, the “Voting and Non-Redemption Shareholders”) pursuant to which the Voting and Non-Redemption Shareholders have agreed with the Company not to redeem up to an aggregate of approximately 16,000,000 Class A Ordinary Shares in connection with the Articles Amendments. Pursuant to the Voting and Non-Redemption Agreements, the Voting and Non-Redemption Shareholders have agreed with the Company to vote in favor of the Amendment Proposals. The Voting and Non-Redemption Agreements provide, among other things, that the Sponsor will transfer up to an aggregate of 8 million Private Placement Warrants. Additionally, On June 12, 2026, the Company, the Sponsor, ReserveOne and Pubco entered into Voting Support Agreements (the “Voting Agreements”) with certain unaffiliated third parties (collectively, the “Voting Shareholders”) pursuant to which the Voting Shareholders agreed with the Company to vote in favor of the Amendment Proposals. As of the Record Date, the Sponsor, who the Company expects to vote in favor of the Amendment Proposals, the Voting and Non-Redemption Shareholders and the Voting Shareholders beneficially owned approximately 74% of the outstanding Ordinary Shares entitled to vote at the Meeting. Accordingly, unless the Sponsor does not vote in favor of the Amendment Proposals, or the Voting and Non-Redemption Agreements and Voting Agreements are terminated in accordance with their terms, the Articles Amendment Proposals will be approved without the need for the affirmative votes of any other shareholders.

Our directors and executive officers do not own any Ordinary Shares of the Company.

Will the Company seek any further extensions to liquidate the Trust Account?

Other than the Extension Proposal, until the expiration of the Extension as described in this proxy statement, the Company does not currently anticipate seeking any further extension to consummate an initial business combination.

What happens if the Extension Proposal is not approved?

If the Extension Proposal is not approved, and we do not consummate the initial business combination by August 2, 2026, we will be required to liquidate and dissolve our Trust Account by returning the then-remaining funds in such account to the Public Shareholders.

The Sponsor has waived its right to participate in any liquidation distribution with respect to their Founder Shares. There will be no distribution from the Trust Account with respect to the Company’s Public Warrants or Private Placement Warrants, which will expire worthless in the event we wind up.

Additionally, redemption payments for Redemption Elections in connection with this Meeting will only be made if the Extension Proposal receives the requisite shareholder approval and we determine to implement the Extension.

If the Amendment Proposals are approved, what happens next?

Subject to the approval of the Articles Amendment Proposals by a special resolution being a resolution passed by a majority of at least two-thirds of the Company’s shareholders who, being present in person (including virtually) or represented by proxy and entitled to vote at the Meeting, vote at the Meeting, the Articles Amendments (in the form of Annex A hereto) will be adopted with immediate effect and the Company will file the same with the Registrar of Companies of the Cayman Islands. Additionally, the Company would proceed to execute the Trust Agreement Amendment (in the form of Annex B hereto). The Company will remain a reporting company under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and its Units, Public Shares and Public Warrants will remain publicly traded. Unless and until the Board determines to wind up the operations of the Company, the Company will continue to work to consummate the initial business combination prior to the Extension Date.

Notwithstanding shareholder approval of the Amendment Proposals, our Board will retain the right to abandon and not implement the Amendment Proposals at any time without any further action by our shareholders.

What happens if the Extension Proposal is approved and any of the other Amendment Proposals are not approved?

If the Extension Proposal is approved and any of other Amendment Proposals are not approved, the Company will continue to attempt to consummate an initial business combination until August 2, 2027.

Would I still be able to exercise my redemption rights if I vote against the Extension Proposal?

Yes, assuming you are a shareholder as of the Record Date and continue to hold your Ordinary Shares at the time of your Redemption Election (and subsequent redemption payment). However, redemption payments for Redemption Elections in connection with this Meeting will only be made if the Extension Proposal receives the requisite shareholder approvals and we determine to implement the Extension. If you do not redeem your publicly held Class A Ordinary Shares, which we refer to as Public Shares, in connection with the Meeting, you will retain your right to redeem your Public Shares upon consummation of an initial business combination, subject to any limitations set forth in the Articles.

What vote is required to approve each proposal at the Meeting?

Approval of the each of the Articles Amendment Proposals, including the Extension Proposal, the Trust Interest Withdrawal Proposal, the Name Change Proposal and the Fairness Opinion Proposal, requires a special resolution under the Articles, being a resolution passed by at least two-thirds of the votes cast by holders of issued and outstanding Ordinary Shares who, being present in person (including virtually) or by proxy, and entitled to vote at the Meeting, vote at the Meeting.

Approval of the Trust Agreement Amendment Proposal and the Adjournment Proposal, if presented, requires an ordinary resolution as a matter of Cayman Islands law, being a resolution passed by the holders of a majority of the issued and outstanding Ordinary Shares who, being present in person (including virtually) or represented by proxy and entitled to vote at the Meeting, vote at the Meeting.

A shareholder’s failure to vote by proxy or to vote in person at the Meeting will not be counted towards the number of Ordinary Shares required to validly establish a quorum. Abstentions and broker non-votes will be counted in connection with the determination of whether a valid quorum is established but will not count as votes cast and therefore have no effect on the Articles Amendment Proposals.

As of the Record Date, the Sponsor, who we expect to vote in favor of the Amendment Proposals, and shareholders who entered into Voting and Non-Redemption Agreements and Voting Agreements beneficially owned approximately 74% of the outstanding Ordinary Shares. Accordingly, unless the Sponsor does not vote in favor of the Amendment Proposals, or the Voting and Non-Redemption Agreements and Voting Agreements are terminated in accordance with their terms, the Articles Amendment Proposals will be approved without the need for the affirmative votes of any other shareholders.

When and where is the Meeting?

The Meeting will be held at 11:00 a.m., Eastern Time, on July 17, 2026, at the office of Troutman Pepper Locke LLP, located at 875 Third Ave, 17 th Floor, New York, New York 10022, United States, and virtually via live webcast or at such other time, on such other date and at such other place at which the Meeting may be adjourned or postponed. The live webcast of the Meeting can be accessed by visiting https://www.cstproxy.com/m3brigadev/ext2026, where you will be able to listen to the Meeting live, ask questions pertinent to the Meeting and vote. The Company’s shareholders may attend and vote at the Meeting in person and/or by visiting https://www.cstproxy.com/m3brigadev/ext2026 and entering the control number found on their proxy card. Shareholders must enter their control number to ask questions pertinent to the Meeting and vote.

How do I register and attend the Meeting?

Registered shareholders received a proxy card from Continental. The proxy card contains instructions on how to attend the Meeting including the URL address, along with a control number that you will need for access. If you do not have your control number, contact Continental by phone at: (917) 262-2373, or email proxy@continentalstock.com.

You can pre-register to attend the live webcast of the Meeting starting July 15, 2026 at 9:00 a.m., Eastern Time. Enter the URL address into your browser https://www.cstproxy.com/m3brigadev/ext2026, enter your control number, name and email address. Once you pre-register, you can vote your Ordinary Shares. At the start of the Meeting you will need to re-log in using your control number and will also be prompted to enter your control number if you vote during the Meeting.

Shareholders who desire to attend the meeting in person are requested to pre-register for the Meeting by contacting the Company’s investor relations team at (212) 355-5515 at least two days prior to the Meeting. Pre-registration is requested to facilitate your admission to the Meeting. While pre-registration is requested, any registered shareholder qualified to vote will not be denied admission solely for failing to pre-register, and any admission and qualification questions will be resolved by the Meeting’s chairperson. If attending in person, please allow ample time to clear any security procedures and check in requirements of the Meeting host.

Beneficial investors, who own their investments through a bank or broker, will need to contact Continental to receive a control number. If you plan to vote at the Meeting, you will need to have a legal proxy from your bank or broker or if you would like to join and not vote Continental will issue you a guest control number with proof of ownership. Either way you must contact Continental for specific instructions on how to receive the control number. Continental can be contacted at the number or email address above. Please allow up to 72 hours prior to the Meeting for processing your control number.

If you do not have internet capabilities, you can attend the Meeting via a listen-only format by dialing 1 (800) 450-7155 (toll-free), or +1 (857) 999-9155 (standard rates apply) outside of the U.S. and Canada; when prompted enter the conference ID number 7673984#. This is listen-only, you will not be able to vote or enter questions during the Meeting.

Who is entitled to vote at the Meeting?

The Company has fixed June 25, 2026 as the Record Date. If you were a Public Shareholder at the close of business on the Record Date, you are entitled to vote on matters that come before the Meeting. However, a Public Shareholder may only vote his or her Ordinary Shares if he or she is present in person (which would include presence virtually at the Meeting) or is represented by proxy at the Meeting.

How do I vote?

If you are a holder of record of Ordinary Shares on the Record Date, you may vote at the Meeting or by submitting a proxy for the Meeting. You may submit your proxy by completing, signing, dating and returning the enclosed proxy card in the accompanying pre-addressed postage paid envelope, or you may submit your proxy via the internet athttps://www.cstproxy.com/m3brigadev/ext2026 by following the instructions on your proxy card.

If you vote by proxy card, your “proxy”, whose name is listed on the proxy card, will vote your Ordinary Shares as you instruct on the proxy card. If you sign and return the proxy card but do not give instructions on how to vote your Ordinary Shares, your Ordinary Shares will be voted as recommended by the Company’s Board “FOR” each of the proposals.

If you hold your Ordinary Shares in “street name,” which means your Ordinary Shares are held of record by a broker, bank or nominee, you should contact your broker to ensure that votes related to the Ordinary Shares you beneficially own are properly counted. In this regard, you must provide the broker, bank or nominee with instructions on how to vote your Ordinary Shares or, if you wish to attend the Meeting and vote in person, obtain a legal proxy from your broker, bank or nominee, which is the only way the Company can be sure that the broker, bank or nominee has not already voted your Ordinary Shares.

Any proxy may be revoked by the person giving it at any time before the polls close at the Meeting. A proxy may be revoked by filing with the Company’s Secretary at the following address: M3-Brigade Acquisition V Corp., 200 Park Avenue, 58 th Floor, New York, NY. 10166, either (i) a written notice of revocation bearing a date later than the date of such proxy, (ii) a subsequent proxy relating to the same Ordinary Shares, or (iii) by attending the Meeting and voting.

Simply attending the Meeting will not constitute revocation of your proxy. If your Ordinary Shares are held in the name of a broker or other nominee who is the record holder, you must follow the instructions of your broker or other nominee to revoke a previously given proxy.

How many votes do I have?

Shareholders are entitled to one vote at the Meeting for each Ordinary Share held of record as of the Record Date. As of the close of business on the Record Date, there were 28,750,000 Class A Ordinary Shares and 7,187,500 Class B Ordinary Shares outstanding.

How do I change my vote?

If you are a registered holder of Ordinary Shares on the Record Date, you can revoke your proxy at any time before the Meeting by (i) delivering a later-dated, signed proxy card prior to the date of the Meeting, (ii) granting a subsequent proxy related to the same Ordinary Shares or (iii) voting in person or virtually at the Meeting. Attendance at the Meeting alone will not change your vote.

If your Ordinary Shares are held in “street name” by a broker or other agent and you wish to revoke your proxy, you should follow the instructions provided by your broker or agent.

How are votes counted?

Votes will be counted by the inspector of election appointed for the Meeting, who will separately count “FOR”, “AGAINST” and “ABSTAIN” votes, and broker non-votes for each proposal. Approval of the Articles Amendment Proposals require a special resolution as a matter of Cayman Islands law, being a resolution passed by a majority of at least two-thirds of the Company’s shareholders who, being present in person (including virtually) or represented by proxy and entitled to vote at the Meeting, vote at the Meeting. The Trust Agreement Amendment Proposal and Adjournment Proposal, if presented, requires an ordinary resolution as a matter of Cayman Islands law, being a resolution passed by a majority of the Company’s shareholders who, being present in person (including virtually) or represented by proxy and entitled to vote at the Meeting, vote at the Meeting.

If a shareholder fails to return a proxy card and does not attend the Meeting in person, then such shareholder’s Ordinary Shares will not be counted for purposes of determining whether a quorum is present at the Meeting. Abstentions and broker non-votes will be counted in connection with the determination of whether a valid quorum is established. If a valid quorum is established, abstentions and broker non-votes will have no effect on the outcome of the proposals. Likewise, abstentions and broker non-votes will have no effect on the proposals.

If my Ordinary Shares are held in “street name,” will my broker automatically vote them for me?

No. If your Ordinary Shares are held in a stock brokerage account or by a bank or other nominee, you are considered the “beneficial holder” of the Ordinary Shares held for you in what is known as “street name.” If this is the case, this proxy statement may have been forwarded to you by your brokerage firm, bank or other nominee, or its agent.

As the beneficial holder, you have the right to direct your broker, bank or other nominee as to how to vote your Ordinary Shares. If you do not provide voting instructions to your broker on a particular proposal on which your broker does not have discretionary authority to vote, your Ordinary Shares will not be voted on that proposal.

This is called a “broker non-vote.” Abstentions and broker non-votes will be counted in connection with the determination of whether a valid quorum is established but will have no effect on the proposals.

For the proposals in this proxy statement, your broker will not have the discretionary authority to vote your Ordinary Shares. Accordingly, your bank, broker, or other nominee can vote your Ordinary Shares at the Meeting only if you provide instructions on how to vote. You should instruct your broker to vote your Ordinary Shares as soon as possible in accordance with directions you provide.

What constitutes a quorum?

The holders of one-third of the issued and outstanding Ordinary Shares of the Company being individuals present in person or by proxy or if a corporation or other non-natural person by its duly authorized representative or proxy (which would include presence virtually at the Meeting) constitute a quorum. In the absence of a quorum, the chairman of the Meeting has the power to adjourn in accordance with the terms of the Articles.

As of the Record Date for the Meeting, 11,979,167 Ordinary Shares would be required to achieve a quorum.

What interests do the Company’s directors and executive officers have in the approval of the proposals?

The Company’s directors and executive officers have interests in the proposals that may be different from, or in addition to, your interests as a shareholder. See “The Meeting — Interests of Our Sponsor, Directors and Officers.”

What happens to the Company’s warrants if the Extension Proposal is not approved and all of the other Amendment Proposals are approved?

If the Extension Proposal is not approved and we do not consummate a business combination by August 2, 2026, we will be required to liquidate and dissolve our Trust Account by returning the then-remaining funds in such account to the Public Shareholders. In that case, the Public Warrants as well as the Private Placement Warrants will be worthless.

What happens to the Company’s warrants if the Extension Proposal is approved and any of the other Amendment Proposals are not approved?

If the Extension Proposal is approved, but the other Amendment Proposals are not approved, the Company will continue its efforts to consummate its business combination until the expiration of the Extension Date and will retain the blank check company restrictions previously applicable to it, and the Public Warrants and Private Placement Warrants will remain outstanding in accordance with their terms. However, the Company would not be able to withdraw any interest from the Trust Account to fund ordinary course expenses or accrued liabilities and therefore may have greater difficulty completing an initial business combination.

How do I redeem my Public Shares?

Pursuant to the Company’s Articles a Public Shareholder may request that the Company redeem all or a portion of its Public Shares if the Extension Proposal is approved and if the Company implements the Extension, for cash equal to the pro rata portion of the funds available in the Trust Account. Based upon the amount in the Trust Account as of June 26, 2026, which was approximately $312,197,620, the Company estimates that the per-share pro rata portion of the Trust Account for the redemption of the Class A Ordinary Shares will be approximately $10.86 at the time of the Meeting.

You will be entitled to receive cash for any Public Shares to be redeemed only if you:

• hold Public Shares or hold Public Shares through Units and you elect to separate your Units into the underlying Public Shares and Public Warrants prior to exercising your redemption rights with respect to the Public Shares; and

• prior to 5:00 p.m., Eastern Time, on July 15, 2026 (two business days prior to the vote at the Meeting), (i) submit a written request to Continental that the Company redeem your Public Shares for cash and (ii) deliver your share certificates (if any) and other redemption forms to the Continental Stock Transfer & Trust Company (the “Transfer Agent”), physically or electronically through The Depository Trust Company (“DTC”).

Holders of Units must elect to separate the underlying Public Shares and Public Warrants prior to exercising redemption rights with respect to the Public Shares. If holders hold their Units in an account at a brokerage firm or bank, holders must notify their broker or bank that they elect to separate the Units into the underlying Public Shares and Public Warrants or if a holder holds the Units registered in its own name, the holder must contact the Transfer Agent directly and instruct it to do so. Public Shareholders may elect to redeem all or a portion of their Public Shares regardless of whether they vote for the Extension Proposal, against the Extension Proposal or do not vote in relation to the Extension Proposal.

Any demand for redemption, once made, may be withdrawn at any time until the deadline for exercising redemption requests and thereafter, only with the Company’s consent, until the implementation of the Extension, or such other date as determined by the Board. If you delivered your Ordinary Shares for redemption to the Transfer Agent and decide within the required timeframe not to exercise your redemption rights, you may request that the Transfer Agent return the Ordinary Shares (physically or electronically). You may make such request by contacting the Transfer Agent at the phone number or address listed at the end of this section.

Any corrected or changed written demand of redemption rights must be received by the Company’s Secretary two business days prior to the vote taken on the Extension Proposal at the Meeting. No demand for redemption will be honored unless the holder’s share certificates (if any) and other redemption forms have been delivered (either physically or electronically) to the Transfer Agent at least two business days prior to the vote at the Meeting.

Public Shareholders seeking to exercise their redemption rights and opting to deliver physical certificates and other redemption forms should allot sufficient time to obtain physical certificates from the Transfer Agent and time to effect delivery. It is the Company’s understanding that shareholders should generally allot at least two weeks to obtain physical certificates from the Transfer Agent. However, the Company does not have any control over this process and it may take longer than two weeks. Public Shareholders who hold their Ordinary Shares in street name will have to coordinate with their banks, brokers or other nominees to have the Ordinary Shares certificated or delivered electronically. There is a nominal cost associated with this tendering process and the act of certificating the Ordinary Shares or delivering them through the DTC’s deposit/withdrawal at custodian (“DWAC”) system. The Transfer Agent will typically charge a nominal fee to the tendering broker and it would be up to the broker whether or not to pass this cost on to the redeeming shareholder. In the event the Extension is not approved or implemented, this may result in an additional cost to shareholders for the return of their Ordinary Shares.

If a Public Shareholder properly demands redemption as described above, then, if the Extension Proposal is approved, the Company will redeem the Ordinary Shares subject to the redemptions for cash. Such amount will be paid promptly. If you exercise your redemption rights, then you will be exchanging your Ordinary Shares of the Company for cash and will no longer own these Ordinary Shares following the implementation of the Extension.

If you are a Public Shareholder and you exercise your redemption rights, it will not result in either the exercise or loss of any warrants. Your warrants will continue to be outstanding following a redemption of your Public Shares and will become exercisable in connection with the completion of the Company’s initial business combination. Holders of Private Placement Warrants do not have redemption rights in connection with the Company’s initial business combination.

If you intend to seek redemption of your Public Shares, you will need to deliver your share certificates (if any) and other redemption forms (either physically or electronically) to the Transfer Agent prior to the Meeting, as described in this proxy statement. If you have questions regarding the certification of your position or delivery of your Ordinary Shares, please contact:

One State Street, 30 th Floor

Attention: SPAC Redemption Team

E-mail: spacredemptions@continentalstock.com

Will how I vote on the Extension Proposal affect my ability to exercise redemption rights?

No. If you have redemption rights, you may exercise your redemption rights irrespective of whether you vote your Class A Ordinary Shares for or against the Extension Proposal or any other proposal described in this proxy statement, or even if you do not vote at all.

If I am a Unit holder, can I exercise redemption rights with respect to my Units?

No. Holders of outstanding Units must elect to separate the Units into the underlying Public Shares and Public Warrants prior to exercising redemption rights with respect to the Public Shares. If you hold your Units in an account at a brokerage firm or bank, you must notify your broker or bank that you elect to separate the Units into the underlying Public Shares and Public Warrants, or if you hold Units registered in your own name, you must contact the Transfer Agent directly and instruct them to do so. If you fail to cause your Public Shares to be separated and delivered to the Transfer Agent by 5:00 pm, Eastern Time, on July 15, 2026, you will not be able to exercise your redemption rights with respect to your Public Shares.

What are the material U.S. federal income tax consequences to U.S. Holders that exercise their redemption rights?

For a description of the material U.S. federal income tax consequences to U.S. Holders (as defined below) that exercise their redemption rights, see the description in the section entitled “The Amendment Proposals — U.S. Federal Income Tax Considerations For Shareholders Exercising Redemption Rights.”

What should I do if I receive more than one set of voting materials?

You may receive more than one set of voting materials, including multiple copies of this proxy statement and multiple proxy cards or voting instruction cards if your Ordinary Shares are registered in more than one name or are registered in different accounts. For example, if you hold your Ordinary Shares in more than one brokerage account, you will receive a separate voting instruction card for each brokerage account in which you hold Ordinary Shares. Please complete, sign, date and return each proxy card and voting instruction card that you receive in order to cast a vote with respect to all of your Ordinary Shares.

Who is paying for this proxy solicitation?

The Company will pay for the entire cost of soliciting proxies. The Company has engaged Sodali & Co. (“Sodali”) to assist in the solicitation of proxies for the Meeting. The Company has agreed to pay Sodali’s customary fees of $20,000, plus expenses and disbursements, and indemnify Sodali against certain damages, expenses, liabilities or claims relating to its services as the Company’s proxy solicitor. In addition to these mailed proxy materials, our directors and executive officers may also solicit proxies in person, by telephone or by other means of communication. These parties will not be paid any additional compensation for soliciting proxies. The Company may also reimburse brokerage firms, banks and other agents for the cost of forwarding proxy materials

to beneficial owners. While the payment of these expenses will reduce the cash available to us to consummate a business combination if the proposals are approved, we do not expect such payments to have a material effect on our ability to consummate a business combination.

Where do I find the voting results of the Meeting?

We will announce preliminary voting results at the Meeting. The final voting results will be tallied by the inspector of election and published in a Current Report on Form 8-K, which the Company is required to file with the Securities and Exchange Commission (the “SEC”). within four business days following the Meeting.

Who can help answer my questions?

If you have questions about the proposals or if you need additional copies of this proxy statement or the enclosed proxy card you should contact:

You also may obtain additional information about the Company from documents filed with the SEC by following the instructions in the section titled “Where You Can Find More Information.” If you are a holder of Public Shares and you intend to seek redemption of your Ordinary Shares, you will need to deliver your share certificates (if any) and other redemption forms (either physically or electronically) to the Transfer Agent at the address below prior to 5:00 p.m., Eastern Time, on July 15, 2026 (two business days prior to the vote at the Meeting). If you have questions regarding the certification of your position or delivery of your share certificates (if any) and other redemption forms, please contact:

Attn: SPAC Redemption Team

One State Street Plaza, 30 th Floor

E-mail: spacredemptions@continentalstock.com