Fury of Kostchtchie

Fury of Kostchtchie
Frost giants who struggle to rise in their ordning, along with those who reject Annam and his children, sometimes turn to the worship of the demon lord Kostchtchie. In the myths of these giants, Kostchtchie was once a frost giant of such tremendous might that he slew a demon lord in single combat, claimed its Abyssal realm for himself, and now waits for other frost giants to join him in conquering the rest of the Abyss.
When Kostchtchie answers the pleas of giants, he gives them supernatural strength and ferocious bloodlust. The giants' muscles expand, their arms extend past their knees, and bitter cold surrounds them. The demon lord's gifts come at a cost, though, as the giants' souls slowly burn away to fuel these newfound powers. Over time, the sensation of burning in the chest intensifies, driving these giants into a frenzy. The newly transformed Fiends quickly find that only combat can numb the burning.