Laguna was right.

You might see me in the darkness *this was the Vincent line
Full of anger at what has happened to me *lame attempt to show limit break through the infliction of pain (attacks, etc)
Better looking than any horror movie
I truely am your nightmare

the last two were the specific limit break. the chainsaw bearing man is pretty much a horror movie idea, and nightmare is the name of his magical attack when in the limitbreak

sorry i suck at riddles