Dante likes to be called Satan…
He's what happens when the witch Medea from Greek mythology is resurrected and possessed by the actual Satan, and impregnated by a psychic "Exorcist" by accident.
He is not able to contain his own power. His mind and body will become (even more) unstable with prolonged access to his power, so it's sealed away in "Levels", going from Negative One to Three. It goes like this… If I were to scale his level of power to that of established fictional characters…
3: Roughly as powerful as Marvel Comics' The Beyonder
2: I wanna say like Amara from Supernatural.
1: Michael in his prime from Supernatural.
0: Alucard from Hellsing
-1: I dunno, maybe he could kick Iron Man's ass…