Being a psyker, and a Chief Librarian at that, Kyras, I don't believe, would kill indiscriminately upon sensing the strangeness of it all, this new world he's awoken to. Ever the thinking man, I presume he would try to get as much information as possible before performing anything devious. Though a traitor, he is still a Blood Raven, and knowledge to him is power.

And contradictory to the one of the Universe's rules or not, Azariah Kyras is canon. I won't defend him being a sorcerer favored by Khorne, but he simply is. And thus I would use him in this RP.