Lord Darius Brenden, Corrupt Noble, is a Unique Ghost found in the Westmarch Commons in Act V of Diablo III. He spawns for The Angered Dead event.
In combat, he has Reflects Damage, Electrified and Knockback affixes. He also summons more Ghosts at his side, and the battle takes place on a very small isolated arena, so kiting will be much complicated.