Appointment of Director Sample Contracts

M3-Brigade Acquisition VI Corp. New York, NY 10019 Re: Appointment of Director Ladies and Gentlemen:
Appointment of Director • August 14th, 2026 • M3-Brigade Acquisition VI Corp. • Blank checks

This letter (this “Letter Agreement”) is being delivered to you in connection with undersigned’s appointment as a director of M3-Brigade Acquisition VI Corp., a Cayman Islands exempted company (the “Company”). Reference is made to the Underwriting Agreement (the “Underwriting Agreement”) entered into by and between the Company and Cantor Fitzgerald & Co., as representative (the “Representative”) of the several underwriters (each, an “Underwriter” and collectively, the “Underwriters”), relating to an underwritten initial public offering (the “Public Offering”), of 34,500,000 of the Company’s units (including up to 4,500,000 units that were purchased to cover over-allotments) (the “Units”), each comprised of one of the Company’s Class A ordinary shares, par value $0.0001 per share (the “Class A Ordinary Shares”), and one- third of one redeemable warrant. Each whole warrant (each, a “Warrant”) entitles the holder thereof to purchase one Class A Ordinary Share at a price of $11.50 per shar

December 2, 2025 M3-Brigade Acquisition VI Corp. 1700 Broadway, 19th Floor New York, NY 10019 Re: Appointment of Director Ladies and Gentlemen:
Appointment of Director • December 5th, 2025 • M3-Brigade Acquisition VI Corp. • Blank checks

This letter (this “Letter Agreement”) is being delivered to you in connection with undersigned’s appointment as a director of M3-Brigade Acquisition VI Corp., a Cayman Islands exempted company (the “Company”). Reference is made to the Underwriting Agreement (the “Underwriting Agreement”) entered into by and between the Company and Cantor Fitzgerald & Co., as representative (the “Representative”) of the several underwriters (each, an “Underwriter” and collectively, the “Underwriters”), relating to an underwritten initial public offering (the “Public Offering”), of 34,500,000 of the Company’s units (including up to 4,500,000 units that were purchased to cover over-allotments) (the “Units”), each comprised of one of the Company’s Class A ordinary shares, par value $0.0001 per share (the “Class A Ordinary Shares”), and one-third of one redeemable warrant. Each whole warrant (each, a “Warrant”) entitles the holder thereof to purchase one Class A Ordinary Share at a price of $11.50 per share