It came from Barkley, Shut Up and Jam Gaiden.
It's a freeware RPG, and it's awesome honestly.
Also maybe I'm interpreting the rules loosely, but it sounds like we could nominate, for instance, Peyton Manning vs Tom Brady from the Madden series. They're fictionalized representations of historical characters, not licensed characters who originate from outside video games.
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Ace Detective in Sir Chris' Police
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