Belial

From Diablo Wiki

Belial is one of the Lesser Evils along with Andariel and Duriel from Diablo II, as well as Azmodan who, like Belial, has yet to appear in the series of games.

Diablo III

Though Belial, the Lord of Lies has not appeared in any of the Diablo games thus far, Blizzard Entertainment has confirmed that Belial will appear in Act II of Diablo III, which means we could also see the remaining Lesser Evil, Azmodan, too. Belial is also said to be in a civil war, which has broken out among the denizens of Hell since the overthrow of the Three Prime Evils and their expulsion to the mortal realm of Sanctuary, during what was known as The Dark Exile. The two warring factions, one led by Belial and one by Azmodan both are said to be vying for control over all of Hell. Two other Lesser Evils also traveled to Sanctuary to aid the Three in their plans, thus leaving Azmodan and Belial as the only remaining Lesser Evils in Hell.

Great Evils
Prime Evils	Baal • Diablo • Mephisto
Lesser Evils	Andariel • Azmodan • Belial • Duriel
Other Evils	Lilith • Lucion • Kabraxis • Xazax • Astrogha • Assur • Gulag