There are monsters living in the catacombs of a graveyard. One gentleman, whom I can remember always wearing a black leather jacket, gets caught up in the mix with this monster/demon society and turns himself into one. There was a guy/monster with a half-moon shaped head. Every monster had their own monstrosities and different abilities. Their ended up being a battle between monsters and man in the end. I think all of it may have started over a girl. Late '80s early '90s film. Anything?

Sanelymad