I vote 3, due to the fact that it's never even used in any game. And think, again, this game would be before Knuckles became a fighter, never mind slowcoach. The characters should have classic moves, with very slight additions. Mighty is based off Sonic, remember that, and thus, Sonic would behave somewhat like Mighty. Tails, is Tails, and Knuckles is Knuckles. Don't change them.