Thanks for the feedback so far. Another question:
Deals with dark powers tend to come at a high price, so what are they getting out of this, aside from a new land added to their domains along with a little godling?
What might Auril have agreed to give up in return for this deal? Or what has she lost that she wasn't expecting to? Tying it in to her somewhat diminished and vulnerable state in the campaign would be helpful.
Well, now she is trapped.
She has essentially lost her divinity by entering Ravenloft.