Baal

Baal is a demon whose full name is Tor'Baalos. He is one of the three Prime Evils, the ruling brothers of the Burning Hells: Diablo, the Lord of Terror; Mephisto, the Lord of Hatred; and Baal, the Lord of Destruction. His title is also the title of Diablo II's expansion, Lord of Destruction, and that expansion tells the story of his march toward Mount Arreat. The artifact he seeks is the Worldstone, the ancient artifact that shapes and protects Sanctuary. The Lord of Destruction expansion is therefore the story of a Prime Evil trying to reach the Worldstone, and of the heroes who try to stop him.

Like all the Great Evils of the Burning Hells, Baal was born from one of the seven heads of the dragon Tathamet. His domain within Hell is the Realm of Destruction, and it reflects what he is. From the beginning, the three Prime Evils did not share power willingly. They fought one another for rule over Hell's legions, and Baal was part of that long conflict. His family line includes his nephew Lucion, his nieces Lilith and Leah, and his grandnephew Rathma. He was not a servant of the other Prime Evils; he was one of them.

During the conflict known as the Sin War, Mephisto pulled his forces back to study why the angels had withdrawn. Baal had no patience for that careful approach. He stormed the Pandemonium Fortress and found that the Worldstone was no longer there. The angels he killed could not tell him where it had gone, but he formed suspicions. Eventually the Prime Evils learned that Sanctuary existed, that the Worldstone anchored it, and that humanity had potential worth winning. The three brothers founded the Triune religion to win humanity, and Baal used the alias Bala while posing as the Spirit of Creation. They kept Sanctuary hidden from the Lesser Evils, the demon powers below the three brothers. That secrecy, together with the Prime Evils' continued interest in humanity's potential, angered the Lesser Evils. The Lesser Evils rebelled and banished the three brothers into Sanctuary. That banishment is called the Dark Exile.

After the Dark Exile, an order of mage-hunters called the Horadrim hunted the Prime Evils and bound them with soulstones. A soulstone is a vessel that holds a demon's essence in the mortal world. Baal's soulstone was cracked, so the Horadrim could not bind him in the usual way. The mage Tal Rasha volunteered to have the broken shard driven into his own body and then to be bound in a tomb beneath the desert. He held Baal with his own will. Tal Rasha's body withered from hunger and thirst until it was no longer entirely his, because Baal slowly took control of it. Baal struggled to break the bonds, and he tormented Tal Rasha's mind by replaying the moment when he was bound, over and over.

Centuries later, Diablo came to Baal's prison in the guise of the Dark Wanderer, and with him came a man named Marius. Their purpose was to free Baal. While the archangel Tyrael held the Wanderer at bay, Baal tricked Marius into pulling the soulstone free. Baal then joined his brother, and Tyrael was captured. Marius escaped with the soulstone. Baal hunted him to a sanitarium in Westmarch, where Marius had hidden. Disguised as Tyrael, Baal listened to Marius tell the whole journey, then took the soulstone, revealed what he was, killed Marius, and burned the sanitarium. With the shard recovered, Baal marched north, killing as he went. By the time he reached the Barbarian lands, his Army of Destruction numbered in the thousands. The Barbarians defended their homeland fiercely. At the gates of Sescheron they tried to parley; Baal killed the emissary and attacked. The survivors fell back to Harrogath, at the foot of Mount Arreat. Baal's goal was the Worldstone inside the mountain, the ancient artifact that shaped and protected Sanctuary.

In the Worldstone Chamber, the heroes who had followed him killed Baal. By then his soulstone had fused with the Worldstone, so the Worldstone itself had become his soulstone, and his soul was sealed inside it. Tyrael destroyed the corrupted Worldstone. That act destroyed Mount Arreat and much of the land around it, which was the cost of removing the corruption. Trapped inside the stone with Tyrael, Baal fought the angel in a shattered realm that reflected the stone's state. The struggle did not end with the destruction. Much later, when the Cult of Terror tried to purge a shard of the Worldstone in the events of Diablo Immortal, Baal was still present, and the struggle continued.

In the era of Diablo III, the witch Adria captured Baal's essence in the Black Soulstone. He was the third Great Evil marked within that stone, after Andariel and Duriel. Like Duriel, Baal longed for the End of Days, and he quickly understood Diablo's plan: Diablo intended to absorb the other evils and become a single Prime Evil. Baal understood that plan because it sought the ending he desired. In Diablo IV, during the Reign of Enmity, a fragment of Rathma's Prophecy called the Burned Parchment was found in the Tormented Ruins. Rathma is Baal's grandnephew, and the fragment foretells Baal's inevitable return alongside Diablo. Mephisto, appearing as the Bloodied Wolf, says the prophecy speaks true and that his brothers are coming to Sanctuary. Baal's present status remains unknown, but the prophecy says he will come back.