Diablo 3: Reaper of Souls - BlizzCon 2013 Trailer

Having seized the Black Soulstone and slain most of the guards protecting it, it now falls to players to track down Malthael and stop him before he unleashes irreversible havoc on the world. Fortunately, a new hero is ready to join the cause and bring Malthael to justice—the Crusader, a fierce melee warrior whose command of the battlefield is matched only by his unwavering conviction and uncompromising dedication to the Light.
Malthael, the fallen Archangel of Wisdom, returns as the Angel of Death in Diablo III's first expansion set: Reaper of Souls.