I don't know how broken this sell will make Never-Winter nights, but would it be possible to make a "Magic Jar" spell.
It would basically drop a corpse with the casters name, and HP = your current HP.
It would then change your appearance to that of the target you possessed (like mask of flesh). It would also make your Strength, Dex, and Con, and HP all the same as the body you possessed, you also get his items. The Corpse on the ground is then a lootable item that can also be picked up. Convo box for choosing between picking up or looting, or attacking. or they can just bash to deal damage.
If you die in the "possessed" body you instead get knocked back to the corpse unless the corpse is either not in your inventory, or not on the current map. If the corpse is in your inventory you come back to where you were standing but only on the ground.
