I doubt a priest of Thor gets spells that can summon fiends.
Edit: @Another Poet: Wasn't necessarily assuming Hel was evil, but she is a death god who doesn't have any priests, and that's been a theory round here for a while now. Personally, I thought it would humanize Durkula a bit to still have to deal with a ditzy Northern God when praying for spells, which would be nice.