Diablo 4: Who are the Prime Evils? Diablo, Baal & Mephisto explained

❘ Updated: 2023-11-06T13:15:00

Blizzard Entertainment

Will the other Prime Evils get Diablo 4 expansions of their own?

The Prime Evils are the three main villains of the Diablo series, but what are they? Here’s everything you need to know about the Prime Evils in Diablo 4.

In the world of Diablo, the three Prime Evils are always lurking in the background. These demonic lords of the Burning Hells are locked in a bitter war against the High Heavens (and often each other) with humanity stuck in the middle. The Prime Evils have invaded Sanctuary, the human world in the series, many times, but they are always defeated and cast back to Hell.

The problem is, they can’t be killed, only banished and imprisoned. So, the rise of the Prime Evils is a constant threat looming over the head of humankind and the angels themselves. As the release of Diablo 4 gets closer, here’s a breakdown of each of the Prime Evils: Mephisto, Baal, and finally, the Lord of Terror – Diablo himself. We’ll also examine the Lesser Evils and why this collection of characters are also important to the story and universe of Diablo 4.

The Prime Evils
- Mephisto
- Baal
- Diablo
The Lesser Evils
- Azmodan
- Belial
- Andariel
- Duriel

The Prime Evils

The Prime Evils are the most powerful demonic Lords of the Burning Hells and are engaged in the Eternal Conflict with the High Heavens. There are only three Prime Evils, Diablo, Mephisto, and Baal. They’re often seen working together, but each often conspires to betray and rule the others. They also cannot be killed, only ever cast back into the void or imprisoned until they rise again.

Realizing that Sanctuary, and the corruption of humanity, is the key to their victory, the Prime Evils now dedicate their time to corrupting and conquering it. As the angels of Heaven are often aloof to humanity and refuse to see their significance, humankind is frequently forced to face the threat of the Prime Evils alone – something the three brothers take advantage of.

The Prime Evils rule different parts of Hell, each having his own realm within it. The Lesser Evils and other powerful demons also have their own realms in Hell, but each is given this as a reward for being a vassal to the Prime Evils, or they took it by force while rebelling against their demonic overlords.

Mephisto: The Lord of Hatred

Mephisto was a powerful boss in Diablo 2.

Out of the three Lords of Hell, Mephisto is the one we’ve seen the least. Diablo is usually the primary antagonist of the series, and Baal also had his time to shine in the final act of Diablo 2, after both his brothers had already been defeated. But when it comes to Mephisto, he only served as the boss of Act 3 in Diablo 2 before being imprisoned back in Soulstone. He had only walked the world for a brief period of time before the heroes caught up to him and ended his plans.

The Lord of Hatred was referenced in Diablo 3, but never seen. Instead, Diablo absorbed him and Baal to make himself ‘The Prime Evil.’ However, Diablo’s defeat at the end of Diablo 3 released Mephisto from the stone and he was cast back to Hell. In Diablo 4, the main villain is the demon Lilith who also happens to be Mephisto’s daughter, meaning her demonic father is likely to play a key role in Blizzard’s next entry.

Mephisto once banished Lilith from Hell after she betrayed him by releasing the angel Inarius from his prison. Lilith and Inarius would then create Sanctuary as a place to escape the Eternal Conflict between angels and demons and their Nephelem children would eventually evolve into humanity. Whatever Lilith’s plans are now she’s returned, her estranged father is bound to be on her hit list.

Mephisto is considered the weakest but most devious of the Prime Evils, usually falling in line behind Diablo while plotting his own agenda. He often appears to mortals in the form of an injured wolf, trying to tempt them into some act of hatred. After returning in Diablo 4, he’s now poised to be the main antagonist of the first Diablo 4 expansion, Vessel of Hatred.

Baal: The Lord of Destruction

Baal attempts to finish what his brothers started.

Baal is the Lord of Destruction and serves as the primary antagonist of Act V of Diablo 2. This is after his brothers have already been defeated and trapped inside Soulstones. Before this, he is released from his prison by Diablo, and the demonic brothers then trap the angel Tyrael in Baal’s place.

Baal had been imprisoned inside a Soulstone embedded into the flesh of a powerful sorcerer called Tal Rasha who would attempt to contain the Lord of Destruction within himself for all eternity. He successfully kept Baal contained but went mad from the various tortures the demon inflicted on him from within. After his escape, Baal pretends to be Tyrael for a time and slays some of the angel’s allies before learning that his brothers have been defeated.

Finding himself the sole Prime Evil, Baal leads an army of demons against the Barbarian Highlands of Harrogoth in an effort to claim the Worldstone. By seizing this powerful object, Baal can reshape reality to his whim, but he is stopped by the same heroes who defeated Diablo. The Worldstone is then shattered by Tyreal to prevent it from falling into demonic hands.

Baal is absent from Diablo 3 as he is still trapped inside a Soulstone. However, his essence is absorbed by Diablo when the Lord of Terror becomes ‘The Prime Evil’ and uses his new powers to attack the High Heavens. Baal is released from Diablo’s control once his brother is defeated and presumably banished back to Hell.

Diablo: The Lord of Terror

Diablo is the most powerful of the Prime Evils.

Diablo is the ultimate villain of the franchise and is essentially Satan in the world of Sanctuary. His main goal is to subjugate both Heaven and the human world, with all life bowing to him as overlord. He’s also the most powerful and patient of the Prime Evils, allowing the schemes of others to progress until he spots the best time to strike – even if it takes centuries, Diablo always has a plan to return from Hell.

In the first Diablo game, the Lord of Terror had been trapped beneath the Cathedral in Tristram before he possessed the body of a young prince called Albrecht and begin his corruption of Sanctuary. However, Albrecht’s brother, Aiden, and his allies would slay Diablo and trap him in a Soulstone, ending the threat. His brother gone, Aiden then embedded Diablo’s Soulstone in his own flesh to contain him but was gradually corrupted by the demon.

In Diablo 2, the Lord of Terror has managed to possess Aiden and travels Sanctuary, releasing both of his brothers and summoning Lesser Evils to do his bidding. Before he can launch an assault on the High Heavens, Diablo is found and defeated by a new band of heroes. However, Diablo had a contingency plan in place. In Aiden’s body, Diablo fathered a human daughter called Leah who he possesses in Diablo 3.

After then consuming the essence of both of his brothers (and the also defeated Lesser Evils), Diablo becomes ‘The Prime Evil’ and assaults Heaven in his new powerful form. He kills many angels but is eventually defeated by Nephalem, a human who has inherited the powers of both angels and demons due to their bloodline tracing back to Lilith and Inarius.

Diablo is likely no longer ‘The Prime Evil’, as he and his brothers will have been separated following his defeat. All three Lords of Hell will have been sent back to the void, where they will eventually respawn in Hell – before plotting the downfall of Sanctuary anew.

The Lesser Evils

While not as powerful as the Prime Evils, the Lesser Evils are still some of the most dominant and influential demons in Hell. Like the Primes, they recognize Sanctuary as the path to victory in the Eternal Conflict and work to subdue it. They often fall in line behind one of the Prime Evils such as Diablo, but sometimes strike out on their own or wage war against their brethren.

The Lesser Evils once formed an alliance against the Primes and banished them from Hell, forcing the Primes to become stranded in Sanctuary. They’ve also been known to side with Lilith in an attempt to escape the Eternal Conflict. There are four Lesser Evils (that we know of) and each one has appeared in the Diablo series at some point, usually as the boss of an Act.

The Lesser Evils are below the 3 Prime Evils.

Andariel: The Maiden of Anguish

Andariel is a powerful succubus and Lesser Evil that joined Diablo’s cause in Diablo 2. She corrupted the Rogue’s monastery and flooded it with demons until she was vanquished by the heroes and sent back to Hell. Her purpose was to hold the region, while Diablo released Mephisto and Baal, slowing down anyone who would come after The Lord of Terror.

While she was defeated, she succeeded in her objective. Andariel was absent in Diablo 3 but returns in Diablo 4, this time in the service of Lilith and against the Prime Evils.

Duriel: The Lord of Pain

Duriel is a massive spiked slug and a Lesser Evil who was tasked by Diablo to ambush the heroes when they invaded the Tomb of Tal Rasha in Diablo 2. Tal Rasha was a powerful sorcerer who was trying to contain Baal in his own body for all eternity, but Diablo succeeded in freeing his brother and left Duriel behind to take out the heroes who had already slain Andariel.

The Lesser Evil was ultimately defeated and cast back to Hell in Diablo 2, then was absent in Diablo 3. However, he returns in Diablo 4, joining Lilith’s coalition against both Heaven and Hell.

Belial: The Lord of Lies

Belial is one of the two Lesser Evils to appear in Diablo 3, having possessed the Emporer of Caldeum, he uses the power of his host to manipulate the Nephalem and distract them while Azmodan’s army moves on Bastion’s keep. The whole thing is part of a plot to bring Diablo back to Sanctuary, but Belial succeeds in making it look like he and Azmodan are the main enemies of Sanctuary.

Once his deception is uncovered, the Nephalem, Tyrael, and their allies defeat Belial and cast him into the Black Soulstone. He is released during the Diablo 3 DLC and is likely plotting his return from Hell.

Lilith isn’t a Prime Evil, but she’s the daughter of one.

Azmodan: The Lord of Sin

Azmodan is a Lesser Evil who made his in-game debut in Diablo 3. The demon laid siege to Bastion’s Keep and appeared to be the last of the Lesser Evils who needed to be defeated. However, Azmodan was actually aiding Diablo, ensuring the Prime Evil could return and conquer Heaven and Sanctuary. He was eventually defeated by the Nephalem and trapped in the Black Soulstone that Diablo would consume, becoming “The Prime Evil.”

After Diablo’s defeat and the destruction of the Black Soulstone by Malphael, Azmodan would be freed and sent back to Hell. He is absent from Diablo 4, but he could crop up in future DLC content.

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