Country of origin: Probably the U.S.
I have very little info.
Through supernatural means (?) somebody (don't know if it's a man or a woman) gains such powers that no average human can stand a fighting chance against him or her. Maybe it's vampirism. It also makes him or her a little bit deranged.
The protagonist , who was probably a meek character before, goes to a bad part of town so that he can exercise his powers on some bad guys in a righteous way. He doesn't want to hurt anybody innocent. Problem is, that no matter how cocky he acts, nobody attacks him. He bumps into some big dude but even that guys says "Excuse me." and keeps going.
I think finally he finds some hoodlums to mess up.
I'm not sure if it was a comedy, it might have been a dark comedy or even a drama.
It's not Suburban Commando (1991).