I read it probably one or two years ago, but I'm pretty sure it was older than that. Its art style was extremely detailed, maybe even too much so. It was quite violent as well (e.g. at some point a character throws a sink or something like that through the body of another one).
The story was about a group of students (maybe high school, not too sure about that) who "build" a Frankenstein-ish monster which should serve them in doing... something? I can't really remember.
The monster at the end rebels against the group and slaughters them all.
They kidnap and maybe rape one of their teachers.
The leader of the group had some kind of "black star", and at some point he meets a fortune teller who tells him that the black star is a mark of great evil and that people like Hitler had one, but also that the boy would be even more successful than them.
I am pretty sure it had an anime adaptation, but it was less gory and wasn't well accepted.
EDIT: I'm absolutely not sure about this, but the title may have been the name of the creature.