NOTE 1. DESCRIPTION OF ORGANIZATION AND BUSINESS OPERATIONS

Keystone Acquisition Corp. (the “Company”) is a blank check company incorporated in the Cayman Islands on November 28, 2025. The Company was formed for the purpose of effecting a merger, amalgamation, share exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses (a “Business Combination”). The Company may pursue an initial Business Combination in any business or industry. The Company is an early stage and emerging growth company and, as such, the Company is subject to all of the risks associated with early stage and emerging growth companies.

As of June 30, 2026, the Company had not commenced any operations. All activity for the period from November 28, 2025 (inception) through June 30, 2026 relates to the Company’s formation, initial public offering (“Initial Public Offering”), which is described below, and subsequent to the Initial Public Offering, identifying a target company for a Business Combination. The Company will not generate any operating revenues until after the completion of a Business Combination, at the earliest. The Company will generate non-operating income in the form of interest income from the proceeds derived from the Initial Public Offering. The Company has selected December 31 as its fiscal year end.

The registration statement for the Company’s Initial Public Offering was declared effective on June 2, 2026. On June 4, 2026, the Company consummated the Initial Public Offering of 28,750,000 units (the “Units” and, with respect to the Class A ordinary shares included in the Units being offered, the “Public Shares”) at $10.00 per Unit, generating gross proceeds of $287,500,000. Each Unit consists of one Class A Ordinary Share, par value $0.0001 per share, and one-half of one redeemable warrant (the “Public Warrants”). Each whole Public Warrant entitles the holder thereof to purchase one Class A Ordinary Share at an exercise price of $11.50 per share, subject to adjustment.

Simultaneously with the closing of the Initial Public Offering, the Company consummated the sale of 8,468,750 warrants (the “Private Placement Warrants”) at a price of $1.00 per Private Placement Warrant, in a private placement to the Company’s sponsor, Keystone International Acquisition Management LLC (“Sponsor”), and Cohen & Company Capital Markets, a division of Cohen & Company Securities, LLC (“Cohen”) and Clear Street LLC, the representatives of the underwriters, generating gross proceeds of $8,468,750. Of those 8,468,750 Private Placement Warrants, the Sponsor purchased 5,593,750 Private Placement Warrants and the underwriters purchased 2,875,000 Private Placement Warrants. Each whole Private Placement Warrant entitles the holder thereof to purchase one Class A Ordinary Share at an exercise price of $11.50 per share, subject to adjustment. The Private Placement Warrants will become exercisable 30 days after the completion of the initial Business Combination.

Transaction costs amounted to $17,871,474, consisting of $5,750,000 of cash underwriting fees, $11,500,000 of deferred underwriting fees, and $621,474 of other offering costs.

The Company’s management has broad discretion with respect to the specific application of the net proceeds of the Initial Public Offering and the sale of the Private Placement Warrants, although substantially all of the net proceeds are intended to be applied generally toward consummating a Business Combination. There is no assurance that the Company will be able to complete a Business Combination successfully. The Company must complete a Business Combination with one or more target businesses that together have an aggregate fair market value of at least 80% of the value of the Trust Account (as defined below) (excluding the deferred underwriting commissions and taxes payable on income earned on the Trust Account) at the time of the agreement to enter into an initial Business Combination. The Company will only complete a Business Combination if the post-transaction company owns or acquires 50% or more of the outstanding voting securities of the target or otherwise acquires a controlling interest in the target sufficient for it not to be required to register as an investment company under the Investment Company Act of 1940, as amended (the “Investment Company Act”).

Following the closing of the Initial Public Offering on June 4, 2026, an amount of $288,218,750 ($10.025 per Unit) from the net proceeds of the sale of the Units, and a portion of the proceeds of the sale of the Private Placement Warrants, were placed in a trust account (“Trust Account”), located in the United States with Efficiency INC. (“Efficiency”) acting as trustee and invested only in U.S. government treasury obligations with a maturity of 185 days or less or in money market funds meeting certain conditions under Rule 2a-7 under the Investment Company Act, which invest only in direct U.S. government treasury obligations, until the earlier of (i) the completion of a Business Combination and (ii) the distribution of the funds held in the Trust Account, as described below.

The Company will provide its holders of the outstanding Public Shares (the “public shareholders”) with the opportunity to redeem all or a portion of their Public Shares upon the completion of a Business Combination either (i) in connection with a shareholder meeting called to approve the Business Combination or (ii) by means of a tender offer. The decision as to whether the Company will seek shareholder approval of a Business Combination or conduct a tender offer will be made by the Company, solely in its discretion. The public shareholders will be entitled to redeem their Public Shares for a pro rata portion of the amount then in the Trust Account (initially anticipated to be $10.025 per Public Share, plus any pro rata interest earned on the funds held in the Trust Account and not previously released to the Company to pay its tax obligations). There will be no redemption rights upon the completion of a Business Combination with respect to the Company’s warrants. The Public Shares subject to redemption were recorded at redemption value and classified as temporary equity upon the completion of the Initial Public Offering in accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 480, Distinguishing Liabilities from Equity (“ASC 480”).

The Company will proceed with a Business Combination only if a majority of the shares voted are voted in favor of the Business Combination. If a shareholder vote is not required by law and the Company does not decide to hold a shareholder vote for business or other reasons, the Company will, pursuant to its amended and restated memorandum and articles of association (the “Amended and Restated Memorandum and Articles of Association”), conduct the redemptions pursuant to the tender offer rules of the U.S. Securities and Exchange Commission (“SEC”) and file tender offer documents with the SEC prior to completing a Business Combination. If, however, shareholder approval of the transaction is required by law, or the Company decides to obtain shareholder approval for business or other reasons, the Company will offer to redeem shares in conjunction with a proxy solicitation pursuant to the proxy rules and not pursuant to the tender offer rules. If the Company seeks shareholder approval in connection with a Business Combination, the Sponsor has agreed to vote its Founder Shares (as defined in Note 6) and any Public Shares purchased during or after the Initial Public Offering in favor of approving a Business Combination. Additionally, each public shareholder may elect to redeem their Public Shares irrespective of whether they vote for or against the proposed transaction or don’t vote at all.

Notwithstanding the above, if the Company seeks shareholder approval of a Business Combination and the Company does not conduct redemptions pursuant to the tender offer rules, the Amended and Restated Memorandum and Articles of Association provides that a public shareholder, together with any affiliate of such shareholder or any other person with whom such shareholder is acting in concert or as a “group” (as defined under Section 13 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)), will be restricted from redeeming its shares with respect to more than an aggregate of 15% of the Public Shares, without the prior consent of the Company.

The Sponsor has agreed to waive redemption rights with respect to any Founder Shares (as defined in Note 6) held and any Public Shares they may acquire during or after the Initial Public Offering in connection with the completion of Business Combination, except that Public Shares held by the initial shareholders will be subject to mandatory redemption upon any diminution of the Trust Account in connection with an extension, and such shares will be entitled to redemption at a price equal to the per share redemption value then held in the Trust Account in connection therewith.

The Company will have until 21 months from the closing of the Initial Public Offering to complete a Business Combination. However, if the Company anticipates that it may not be able to consummate a Business Combination within such period, the Company may seek shareholder approval to amend the Amended and Restated Memorandum and Articles of Association to extend the date by which the Company must consummate the initial Business Combination. If the Company seeks shareholder approval for an extension, holders of public shares will be offered an opportunity to redeem their shares, regardless of whether they abstain, vote for, or vote against the Company’s initial Business Combination, at a per share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned thereon (which interest shall be net of taxes paid or payable, divided by the number of then issued and outstanding public shares, subject to applicable law).

There is no limit on the number or length of extensions that the Company may seek; however, the Company does not expect to extend the time period to consummate the initial Business Combination beyond 36 months from the closing of the Initial Public Offering. If the Company determines not to, or is unable to, extend the time period to consummate the initial Business Combination, or fails to obtain shareholder approval for such an extension, the Sponsor, management team and other initial shareholders will lose their entire investment in the Founder Shares, except to the extent such holders are entitled to receive liquidating distributions from assets outside the Trust Account.

In order to protect the amounts held in the Trust Account, the Sponsor has agreed that it will be liable to the Company if and to the extent any claims by a third party for services rendered or products sold to the Company, or a prospective target business with which the Company has entered into a written letter of intent, confidentiality or other similar agreement or business combination agreement, reduce the amount of funds in the Trust Account to below the lesser of (i) $10.025 per Public Share and (ii) the actual amount per Public Share held in the Trust Account as of the date of the liquidation of the Trust Account, if less than $10.025 per Public Share due to reductions in the value of the trust assets, in each case less taxes payable and up to $100,000 of interest to pay liquidation expenses, provided that such liability will not apply to any claims by a third party or prospective target business who executed a waiver of any and all rights to the monies held in the Trust Account (whether or not such waiver is enforceable) nor will it apply to any claims under the indemnity of the underwriters of the Initial Public Offering against certain liabilities, including liabilities under the Securities Act of 1933, as amended (the “Securities Act”).