Tyrfing
Tyrfing is the cursed sword of the Hervarar saga, forged by the dwarves Dvalinn and Dulinn for King Svafrlami. When the king forced the dwarves to give him the finest blade they could make, they laid a curse upon it in return: the sword would never miss a stroke, never rust, would kill a man every time it was drawn, and would be the cause of three great evils. After killing the dwarves, Svafrlami was himself slain in a duel with the berserk Arngrímr, and the blade passed into the hands of Arngrímr's sons. The shield-maiden Hervör later raised the sword from the barrow of her dead father Angant