Who is Nanoha Takamachi? 
Oh Recent, maybe
Haruyuki Arita of Accel World, I mean he has some sob backstory, but I wouldn't call it a ridiculously one. Ironical he definitely is a "wimp" in the beginning of the series.
Or
Kurokami Medaka from Medaka Box, though her "ditch" of her friends/morals was well beyond her control, though she definitely overpowered
.