Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We hereby consent to the use in the Prospectus constituting a part of this Registration Statement on Form S-1 of our report dated June 21, 2024, relating to the financial statements of Black Spade Acquisition II Co for the period from May 9, 2024 (inception) through May 22, 2024, which is contained in that Prospectus. We also consent to the reference to us under the caption “Experts” in the Prospectus.

/s/ WithumSmith+Brown, PC

New York, New York 

June 21, 2024