The demons of the Burning Hells have long desired to invade the realm of men. To this end, a powerful group of demon lords known as the Lesser Evils exiled their brethren, the Prime Evils, from the Hells and sent them to the human world of Sanctuary.
War came with them. The Prime Evils—Diablo, Mephisto, and Baal—began corrupting humans, twisting them into dark servants, and poisoning their minds with false promises of power and wealth.
Today, few survivors tell tales of the Prime Evils. Those who saw the Prime Evils’ devastation firsthand remember that two of the Lesser Evils yet live in the Burning Hells…Azmodan, the Lord of Sin, and Belial, the Lord of Lies. These great demons have not forgotten the world of Sanctuary—indeed, they see a chance to seize it for themselves.