So, I once read this really interesting, really dark manga about a witch. It started out set in modern Japan with a string of murders. The murderer and his accomplice are leading up to a ritual sacrifice to summon a witch. In someway that I can't clearly remember, the witch appears and she and the murderer end up in the renaissance? I think that's what it was. And then the murderer becomes known for his cruelty or something. Then the witch somehow ends up back in modern Japan and is running a corner store and these people show up, and I'm not very clear on the story after that. I can't remember the name for the life of me... anyone know?

I think I know this one. Was there a part with Jack the Ripper?

Mephisto.

Fantastic! It was definitely Mephisto! Thanks you guys!