Nihlathak

Nihlathak is the last surviving elder of Harrogath, driven by grief and guilt as his clan's defense of the Worldstone collapses. Nihlathak is a summoner with a vast mob of minions that he uses as his weapons. He has no melee strikes at all, and only a chilling Arctic Blast spell for direct damage. The real danger comes from his use of the Corpse Explosion skill, which he uses to detonate the corpses of fallen monsters which deal substantial fire and physical damage. Skills that destroy corpses are helpful to employ around him, including some of the Druid's Vines, or the Paladin's Redemption. Items that grant "Slain Monsters Rest in Peace" including the Nature's Peace unique Ring, are also effective. People kill Nihlathak repeatedly in Hell mode to collect Keys of Destruction. Additionally, he grants one of the highest amounts of experience, leading to many would-be 99'ers adding him into their rotation of along with Diablo and Baal.