"Fascinating! May I, mmm, have just the most incremental amount of your blood in order to confirm a theory? No? Well, then, I suppose I am, mmm, bloody well out of luck. A ha. A ha ha ha."
It is unclear where Damask comes from, other than that he belongs to the House Hendrake of another universe and is apparently the son of someone who looks exactly like Kozue.
Michelle was apparently supposed to help him get back to his universe due to her experience with the Cave of Worlds, but she and Atsuko? appear to have adopted him into their harem instead.
It's hard to tell quite how he feels about this, because, based on all available evidence, he is a complete freak.