Like the previous Diablo titles from Blizzard, there's totally a giant main boss named "Diablo" in Diablo 3. Surprise! And during Diablo 3 art director Christian Lichtner's GDC 2012 track keynote, attendees were offered a look at the main baddie across his entire evolution. Second surprise: he looks terrifying!
Two decades have passed since the demonic lords, Diablo, Mephisto, and Baal, set out across the world of Sanctuary on a vicious rampage, twisting humanity to their unholy will. Yet for those who battled the Prime Evils, the memory fades slowly. When Deckard Cain returns to the ruins of Tristram Cathedral seeking clues to defeat new stirrings of evil, a fiery harbinger of doom falls from the heavens, striking the very ground where Diablo once entered the world. This fire from the sky reawakens ancient evils and calls the heroes of Sanctuary to defend the mortal world against the rising powers of the Burning Hells once again.