[SixOfSpades]

I can't speak for Valen, but I know that normal Vampires aren't immune to Level Drain. I took a jaunt down to Bodhi's pad the other night, and hit a cluster of them with a couple of False Dawns, which makes all Undead in the area effect become Confused for one round. They started smackin' each other up, and I noticed that they were Level-Draining each other. I didn't really note down whether they were Fledgling Vampires or the more powerful versions, though.