You have absolutely no idea what you're talking about. Either that or you're joking, but the way you described it sounds to me like you have no idea what you're talking about.
K. Rool wasn't in Melee except as a mere trophy. K. Rool has never been playable in Smash Bros.
The only thing close to what you're saying is Mewtwo. And Mewtwo wasn't OP in Melee, he was ****. No, seriously, he played like crap, not many people really liked Mewtwo in Melee (however, people did want Mewtwo to return, they just wanted him to be better).
The other choices are Dr. Mario, Pichu, Roy, and Young Link. None of them are OP, although Dr. Mario and Young Link are better than the characters they were cloned from. The other two were worse.
EDIT:
Oh, and one more thing. You are definitely not One of Us. If you were One of Us then you'd have known this crap to begin with.