Yea good luck with that.

They dine not on blood but on death. If there's life it comes from blood. But blood letting is simply the power over it. Or its struggle to live.

Old magik simply used blood magic to invoke the supposed power over death. I can't tell you how that work. I can only imagine how they killed and killed and sacrificed and ate. But they also sooner died. Death comes for all.

There are plenty of cannibals but no Vamps not in the immortal sense. Yes hahaha they obviously need a transfusion, transplant, or some blood as they die, obviously, they wanted their youth.

You wanted to summon a flesheater, or death? Because of immortality. A childish fable.

What causes blood to be spilled, the hearts of men, mankind. Our nature, our blood.