Frostmourne

Frostmourne runeblade of damned thirst of blood is the runeblade that Ner'zhul, the former Lich King, thrust from his Frozen Throne, intending that Arthas — his unwitting potential host — would discover it on the continent of Northrend. It is currently wielded by the new Lich King Arthas.Frostmourne is an artifact of great evil and tremendous might, forged by demons to hold the Lich King's powers. Ner'zhul thrust the blade out of the Frozen Throne and masterminded it finding its way into Arthas' hands. Desperate for any power that might defeat the Scourge, the arrogant prince Arthas took possession of the runeblade and in doing so sealed his doom as Ner'zhul had planned.