I keep hearing of all this stuff, especially from X-Treme Crazy, that Ace is a "Gary-Stu".
The only Gary-Stu trait I've seen are that Ace has both super powers and a weapon (the Guardian-Strike sword), as for being the "greatest super-hero", those gullible people Acmetropolise are such suck-ups, and his popularity is a referrance to Bugs Bunny's popularity (like how Duck's being hated by people, like they hate his ancestor, Daffy).
And I don't see any girls start chasing after Ace and scream out his name.
So either is not a Gary-Stu, or he is and I need better glasses.
I don't much knowledge to what makes a Gary-Stu/Mary-Sue (except for being Mr./Miss Perfect) Cause people keep changing the facts what makes them fawl-less like they don't have a clue either.