Random Generator gave me Dakmor Ghoul and Eye of Ramos. I like Highway Robber and all, but that would be despite the too expensive cost. This looks acceptable to me, but might require playing to see if I'm missing something.

Slightly unusual as a targeted ability that adds mana. It can't be played as a mana ability, for example in the middle of another spell resolving. But that's not necessarily a problem.

I quite like the Blood Pet/Basal Sliver kind of black mana acceleration, and tying it to a medium-sized life swing sounds good to me. I always liked Parasitic Strix and Blind Hunter.