Make fire giants (possibly only in the Valkyrie quest, possibly others) spellcasters who can only cast a fireball spell. Or, to avoid a flavor issue with giants being not very smart to be good at spells, flavor it as something other than a spell (it could also be implemented as a new attack type).

The Valkyrie quest home level should not be all ice. It seems like a frozen lake currently.

The Norn and Valkyrie quest friendlies have different messages if you talk to them after having been changed into a man.