Thanks bunches, Alzrius and joshhg, you guys rock too.
Needing to be female... well, this is DnD, the game that brought us the Girdle of Masculinity/Femininity, hard but do-able. I wonder if Changelings count?
Losing a level to a succubus draining attack... hmmm... have to do that before I go for the immunity to energy drain class feature, the real problem is getting them to just take one.
But killing a loved one?!? I can't even consider that! I mean, I'd have to actually LOVE someone first for the sacrifice to work and the world is only composed of useless meat puppets born to dance to my will!
Oh, wait, someone who loves ME. Never mind then...
Needless to say, I'm ordering this one straight from Paizo. Keep up the good work, Dragoneers...