Aizen's just bored. He likes to watch others fail. I mean, why else would you gather that bunch of misfits?Chaoshadow said:I dunno, I think most villains are overpowered
But look at Aizen from Bleach, massively overpowered but still has an army behind him
OT: Villains can't really trust anyone, but they still need servants/subordinates.
Hero's...well, of course they need each other. They complete each other.