Heck with it, here's what I believe is going on.

Kukri was the Ancient Vampire. Kagemusha one of his slaves. Atheotes may have been the second one, or there could be another still alive who isn't killing just so as to ambush us near the end. I wouldn't do that myself, but there's no accounting for strategy. In any case, the important thing for right now:

The "special role" is the vampire Nikolaos, and he is a competitive, emergent Mafia. When Kukri died, he took over and is probably now allied with Kagemusha. Both of them are killing.