Ari closes his eyes and begins to recite a lecture from his uncle. "Diablo is the Lord of Terror, one of the three Prime Evils and the seven Lords of Hell, along with Mephisto, Lord of Hatred; Baal, Lord of Destruction; Azmodan, Lord of Sin; Belial, Lord of Lies; Duriel, Lord of Pain; and Andariel, Maiden of Anguish. He is the youngest and the most terrible of the Evils. Twenty years ago, he was defeated by a trio of heroes, but they knew he could not be slain for good, only returned to Hell. Seeking to contain his power, their leader foolishly took Diablo's soul within himself. It was not long before he was corrupted by the Lord of Terror, and became his new vessel. He then freed his brothers Mephisto and Baal, and began a plot to control humanity with an ancient artifact called the Worldstone. However, he was slain by a great hero, and his essence was banished back to the Burning Hells where it belongs."
He opens his eyes again. "Except that hit kind of a snag, because I'm pretty sure that guy who turned into Diablo was my dad, and he sired me after he started turning into Diablo. And I am... Diablo-like, in certain ways. So I think actually his essence might still be around. In me. I don't honestly know how concerning that is! I mean, I didn't grow horns and start killing people, that's cool. But maybe there's some trap lying around in my brain and if somebody says 'cranberry bog' to me on the full moon I'll turn into him for good, or something. I dunno. What I do know is that Uncle Deckard probably knows a hell of a lot more than he told me, and I'm gonna make him tell me everything the second I get back to Sanctuary."