Here's a list, I'm not explaining why, figure it out yourself or something, I dunno...

Luigi (Super Mario)
Rosalina (Super Mario)
Q (Street Fighter)
Dee Jay (Street Fighter)
Guy (Street Fighter)
Ramlethal Valentine (Guilty Gear)
Millia Rage (Guilty Gear)
Mimikyu (Pokémon)
Mewtwo (Pokémon)
Taranza (Kirby)
Anti-Venom (Marvel Comics)
Chasm (Marvel Comics)
Scarecrow (DC Comics)
Axl (Mega Man X)
Whisper the Wolf (Sonic (specifically the comics))


If I were to tell you why all these characters, we would be here forever, and that's not even all of them. I could explain a few if someone wanted me to, though.