Pretty sure he will stay the way he is. He will brood about being mind controlled by the Jailer in the next tie in novel, but in game he will continue being idealistic, nice and powerful. Yaaawn. He just got a cool paint job. A very cool one to be fair.
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He isn't much of a bad guy so far. Sure he keeps souls in the Maw, but that is his job. Dunno why we should care about him or what he does. He was somebody before he did something and now he has to act as a Jailer, but he wants to prove a point and for that he needs four keys. If not for his scary looks and deep voice, he would be a quest giver. A sidequest giver. Gimme all the keys and I will make your ancestral sword even cooler looking.
Hopefully 9.1 will reveal enough of his plans to make us (or rather me, I don't speak for everyone) care.