Exhibit 2.1

Execution Version

FIRST AMENDMENT

TO THE

BUSINESS COMBINATION AGREEMENT

This First Amendment (this “First Amendment”) to the Business Combination Agreement dated as of March 19, 2026 amends the Business Combination Agreement, dated as of November 19, 2025 (the “Original Agreement,” as amended pursuant to this First Amendment and as may be further amended, supplemented, modified and/or restated from time to time, the “Business Combination Agreement”), by and among (i) Blue Acquisition Corp., a Cayman Islands exempted company, “SPAC”), (ii) Blockfusion Data Centers, Inc., a Delaware corporation (“Pubco”), (iii) Atlas I Merger Sub, a Cayman Islands exempted company and a wholly-owned subsidiary of Pubco (“SPAC Merger Sub”), (iv) Atlas Merger Sub, Inc., a Delaware corporation and a wholly-owned subsidiary of Pubco (“Company Merger Sub”), and (v) Blockfusion USA, Inc., a Delaware corporation (together with its successors, the “Company”). Capitalized terms used but not defined herein shall have the meanings ascribed to them in the Business Combination Agreement.

RECITALS:

WHEREAS, Section 10.8 of the Business Combination Agreement sets forth that the Business Combination Agreement may be amended, supplemented or modified only by execution of a written instrument signed by each of the Parties; and

WHEREAS, the Parties desire to amend certain provisions of the Original Agreement, including to increase (i) the Incentive Plan from five percent (5%) of the aggregate number of shares of Pubco Common Stock issued and outstanding immediately after the Closing to eight percent (8%) of the aggregate number of shares of Pubco Common Stock issued and outstanding immediately after the Closing, and (ii) the size of the Post-Closing Pubco Board from seven individuals to nine individuals.

NOW, THEREFORE, in consideration of the foregoing and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, and in accordance with the terms of the Business Combination Agreement, the parties hereto, intending to be legally bound, do hereby acknowledge and agree as follows:

1.  Amendments to the Original Agreement.

(a)  The second sentence of Section 6.12(a) of the Original Agreement is hereby replaced with the following:

“As promptly as practicable after the date hereof, SPAC, Pubco and the Company shall prepare, and file with the SEC a registration statement on Form S-4 (as amended or supplemented from time to time, and including the Proxy Statement contained therein, the “Registration Statement”) in connection with the registration under the Securities Act of the Pubco Class A Common Stock to be issued under this Agreement to the holders of SPAC Ordinary Shares, SPAC Rights and to the Company Stockholders pursuant to the Mergers, which Registration Statement will also contain a proxy statement (as amended, the “Proxy Statement”) for the purpose of soliciting proxies from SPAC shareholders for the matters to be acted upon at SPAC Extraordinary General Meeting and providing the Public Shareholders an opportunity in accordance with SPAC’s Organizational Documents to have their SPAC Public Shares redeemed (the “Redemption”). The Proxy Statement shall include proxy materials for the purpose of soliciting proxies from SPAC shareholders to vote, at an extraordinary general meeting of SPAC shareholders to be called and held for such purpose (the “SPAC Extraordinary General Meeting”), in favor of resolutions approving (i) the adoption and approval of this Agreement, the Ancillary Documents and the transactions contemplated hereby or referred to herein, including the Mergers (and, to the extent required, the issuance of any shares in connection with Transaction Financing, if any), by the holders of SPAC Ordinary Shares in accordance with SPAC’s Organizational Documents, the Act, the DGCL and the rules and regulations of the SEC and NASDAQ, (ii) the adoption and approval of the Amended Pubco Charter (as hereinafter defined), (iii) adoption and approval of a new equity incentive plan for Pubco in a form satisfactory to SPAC and Company (the “Incentive Plan” or “Post-Closing Equity Plan”), and which will provide for awards for a number of shares of Pubco Class A Common Stock equal to eight percent (8%) of the aggregate number of shares of Pubco Common Stock issued and outstanding immediately after the Closing (after giving effect to the Redemption), as further set forth in the Incentive Plan, (iv) the appointment of the members of the Post-Closing Pubco Board in accordance with Section ‎6.17 hereof, (v) such other matters (or, to the extent applicable, excluding such approval matters) as the Company and SPAC shall hereafter mutually determine to be necessary or appropriate in order to effect the Mergers and the other transactions contemplated by this Agreement (the approvals described in foregoing clauses (i) through (v), collectively, the “SPAC Shareholder Approval Matters”), and (vii) the adjournment of SPAC Extraordinary General Meeting to a later date or dates, if necessary or desirable in the reasonable determination of SPAC. If on the date for which SPAC Extraordinary General Meeting is scheduled, SPAC has not received proxies representing a sufficient number of shares to obtain the Required SPAC Shareholder Approval, whether or not a quorum is present, SPAC may make one or more successive postponements or adjournments of SPAC Extraordinary General Meeting. In connection with the Registration Statement, SPAC, Pubco and the Company will file with the SEC financial and other information about the transactions contemplated by this Agreement in accordance with applicable Law and applicable proxy solicitation and registration statement rules set forth in SPAC’s Organizational Documents, the Act, the DGCL and the rules and regulations of the SEC and NASDAQ. The Company shall promptly provide SPAC and Pubco with such information concerning the Target Companies and their stockholders, officers, directors, employees, assets, Liabilities, condition (financial or otherwise), business and operations that may be required or appropriate for inclusion in the Registration Statement, or in any amendments or supplements thereto, which information provided by the Company shall be true and correct and not contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements made, in light of the circumstances under which they were made, not materially misleading.”

(b)  Section 6.17(a) of the Original Agreement is hereby replaced with the following:

“(a) The Parties shall take all necessary action, including causing the directors of the Pubco to resign, so that effective as of the Closing, Pubco’s board of directors (the “Post-Closing Pubco Board”) will consist of nine (9) individuals. Immediately after the Closing, the Parties shall take all necessary action to designate and appoint to the Post-Closing Pubco Board (i) two (2) persons designated by SPAC prior to the Closing (the “SPAC Directors”), at least one (1) of whom shall be required to qualify as an independent director under NASDAQ rules, (ii) six (6) persons that are designated by the Company prior to the Closing (the “Company Directors”), at least three (3) of whom shall be required to qualify as an independent director under NASDAQ rules and (iii) one (1) additional director who shall qualify as an independent director under NASDAQ rules, to be mutually agreed on prior to the Closing by SPAC and the Company. At or prior to the Closing, Pubco will provide each member of the Post-Closing Pubco Board with a customary director indemnification agreement, in form and substance reasonably acceptable to such director.”

2.  Miscellaneous. Except as expressly provided in this First Amendment, all of the terms and provisions in the Original Agreement shall remain unchanged and in full force and effect, on the terms and subject to the conditions set forth therein. This First Amendment does not constitute, directly or by implication, an amendment or waiver of any provision of the Original Agreement, or any other right, remedy, power or privilege of any party, except as expressly set forth herein. Any reference to the Business Combination Agreement in the Business Combination Agreement or any other agreement, document, instrument or certificate entered into or issued in connection therewith shall hereinafter mean the Original Agreement, as amended by this First Amendment (or as the Business Combination Agreement may be further amended or modified after the date hereof in accordance with the terms thereof). The Original Agreement, as amended by this First Amendment, and the documents or instruments attached hereto or thereto or referenced herein or therein, constitutes the entire agreement between the parties with respect to the subject matter of the Business Combination Agreement, and supersedes all prior agreements and understandings, both oral and written, between the parties with respect to its subject matter. If any provision of the Original Agreement is materially different from or inconsistent with any provision of this First Amendment, the provision of this First Amendment shall control, and the provision of the Original Agreement shall, to the extent of such difference or inconsistency, be disregarded. Sections 10.1 through 10.9 and 10.11 through 10.13 of the Original Agreement are hereby incorporated herein by reference as if fully set forth herein, and such provisions apply to this First Amendment as if all references to the “Agreement” contained therein were instead references to this First Amendment.

[Remainder of Page Intentionally Left Blank; Signature Pages Follow]

IN WITNESS WHEREOF, each party has caused this First Amendment to be signed and delivered by its respective duly authorized signatory as of the date first written above.

[Signature Page – First Amendment to Business Combination Agreement]

IN WITNESS WHEREOF, each party has caused this First Amendment to be signed and delivered by its respective duly authorized signatory as of the date first written above.

[Signature Page – First Amendment to Business Combination Agreement]

IN WITNESS WHEREOF, each party has caused this First Amendment to be signed and delivered by its respective duly authorized signatory as of the date first written above.

[Signature Page – First Amendment to Business Combination Agreement]