Is it possible, lore-wise, to be both Werewolf and Vampire at the same time? It's not possible in Skyrim, but was in Morrowind iirc. If it is, what happens to the soul of the person when he/she dies? Does the soul go to Coldharbour of Molag Bal, or the Hunting Grounds of Hircine?
It's not possible, at least I don't think it is. Morrowind was a glitch. There is a reason you can't contract both diseases in Skyrim.
Kynareth suffocates them for crimes against nature/good taste.
Pfft. Please, screw Kynareth. They are the top of the food chain, which is why everything else deserves to be drained to a bloodless husk or devoured as a juicy piece of tidbit or lamshank.