I would only add that the presence of an emotion in and of itself does not guarantee a certain type of behavior.
I completely agree. My main point was that while love may not unquestionably determine a character's actions, it would seem that love is an emotion that humans/bipedals experience to keep the parents of an offspring together. This is necessary (of course) due to the exceptionally slow development of human/bipedal offspring and the resulting dependancy on a strong parental complex. Since Valen is undead and cannot produce offspring (or at least give birth to them) there would presumably be no need for a love.
Anyway, I am in full support of what you are doing and am eagerly awaiting the expansion. A Valen 'romance' or 'seduction' or whatever it is does make sense in the respect that it will add depth to a very dark character. And even though I still hold the above opinion, I cannot argue with that. Therefore, get the damn thing done so we can indulge in multi-faceted satanic insanity.