isnt it just a life leech, and only on male characters?
Are you thinking of Semidar (giant succubus from Abyss Champion Spawn)? She is the one that reflects damage to male chars.
Normal succubii only has the AOE damage attack. Which affects both male and female characters. It's just life drain I think. Doesn't seem to leech HP. I've never thought about it having a damage type...
Kenetic eater seems to be physical damage. But I never paid attention to what damage I was taking whenever the one from my ranger cloak fire off once in a while.