Ireth
Myth Weaver
Personally, I look for villains that are either misdirected or misunderstood. There's very little 'take over the world' motives that can be believable. I prefer the villains I write to be tragic - meaning they're essentially good, but have one major flaw. Whether that flaw be pride or inflexibility is up to me at the time I write them. But this makes the story interesting in my opinion. People in real life are rarely all good or all bad. It's important to me that my writing reflects that element of reality.
I think the villain of Low Road might fall into your interests. Conall is completely insane and seen by the hero as evil, but he sincerely believes he's doing the right thing for his people, providing them with a steady supply of humans to feed from, and even providing for the human captives' needs in a twisted way, by feeding them the flesh of their slain companions. (Waste not, want not!) The Goddess responsible for creating the vampires even tells them that they are to take humans as well as animals for their prey, so Conall is serving Her quite well in doing so. It's not his fault he was made what he is by a Goddess of darkness and death.