Aspect of Hatred, Mephisto's Disciple, is a unique Morlu Incinerator found in Silver Spire Level 2 in Diablo III.
In Campaign, it spawns as Deckard Cain's ghost, revealing its true self after players talk to it. Killing it is not mandatory.
In combat, it has Electrified and Thunderstorm affixes, and in addition its innate Repulsion ability deals considerable damage.