There was a perverse side of me, with things like Van Helsing coming out. I didn't want to go down that route.
I believe the most intricate plot won't matter much to readers if they don't care about the characters, especially in a series. So I try to focus hard on making each character, whether villain or hero, have an interesting flaw that readers can relate to.
It's often just enough to be with someone. I don't need to touch them. Not even talk. A feeling passes between you both. You're not alone.