Diablo, al'Diabalos, The Prime Evil, also known as The Lord of Terror, is the main antagonist and the title character in the Diablo franchise. He is one of the Prime Evils, the three most powerful demons in the Burning Hells, and is one of the most prominent characters both in the games and in the books based on the Diablo series. The deity Dialon, the spirit of Determination of the church of the Triune, is in reality Diablo.
Diablo is one of Three; a Prime Evil, alongside his brothers Baal and Mephisto. Diablo was originally created from one of the seven heads of Tathamet along with the other Great Evils. Together with his two brothers he ruled over the Burning Hells for untold ages and led the armies of Hell against the Heavenly Host of the High Heavens.
 The Sin War
When Sanctuary was discovered by Hell first, he and his brothers quickly realized the potential mankind possessed and so created the Triune to lure mortals to aid their cause against Heaven. The Three stayed outside of Sanctuary until the time of the Sin War when Uldyssian and his followers began to challenge the power of both the Triune and the Cathedral of Light. At this time, Diablo personally traveled to Sanctuary in order to seal a pact with Inarius whereby they would work together to capture Uldyssian and eliminate the threat the edyrem posed. The plan involved Diablo trying to subdue Uldyssian, which he attempted through coercion and trickery. When Uldyssian saw through his scheme, Diablo tried instead to unleash his power of terror over the human to cause his deepest fear to surface, but for a brief moment Uldyssian managed to turn the Lord of Terror's powers against himself, causing instead Diablo to flee in terror:
The shadowy figure let out a shriek that nearly made Uldyssian flee in mindless panic. Somehow, though, the son of Diomedes held. To do otherwise was to fail.
Diablo twisted and turned as his own insidious power wreaked havoc on him. He had only glanced for a moment, but the fears of the master of fear were evidently monstrous, indeed.
Still howling, Diablo rushed up into the ceiling — and through the very stone. His cry echoed throughout not only the underground passage but Uldyssian’s soul.
The encounter seemed to have left Diablo temporarily hesitant for a few days afterwards, as Mephisto later turns up to negotiate the terms of the treaty between Heaven and Hell regarding the fate of Sanctuary:
YOU OFFER PARLEY…LORD MEPHISTO? Auriel asked the shadow. YOU…NOT YOUR BROTHER?
The shadow coalesced somewhat into a tall, macabre shape that instantly brought to Mendeln’s mind the monstrous morlu or, worse yet, their heinous master, Lucion, who, like Lilith, was also offspring of this sudden and dread visitor.
“My dear brother is beside himself. Therefore, I, who am also supreme, do indeed offer parley — and more!
The Three immediately began to scheme on how to upset the truce shortly after its creation, something that the Lesser Evils, particularly Azmodan and Belial, did not like. In an effort to preserve the truce, the Lesser Evils began a civil war against the Prime Evils that lasted for an unspecified but long time. The conflict did not end until the minions of the Prime Evils themselves turned on their masters. The Three were then exiled to Sanctuary, and thus began the Dark Exile.
 The Dark Exile
As the Three appeared on Sanctuary they were very weak and roamed the world for forty years, spreading terror, destruction and hatred wherever they went. Eventually however the Horadrim, a united order of mages, was created by Tyrael to hunt down and imprison the Prime Evils. Diablo was the last to be captured, nine years after Baal was buried in Aranoch, and his soulstone inside which he was imprisoned was buried at the bottom of a labyrinth beneath the Tristram Cathedral in Khanduras. The Horadrim tried to maintain their guard, but with the immediate threat of the Three gone the order dissipated and the charge of guarding Diablo was lost.
 Diablo I
There he remained for close to 180 years until Leoric arrived from the east, proclaiming himself king of Khanduras and chose Tristram as his new capital. His close advisor, Lazarus, was an archbishop of the Zakarum church, which had at the time been infiltrated and taken over by Mephisto. Lazarus had insisted Leoric choose Tristram as his capital, and soon after arriving the archbishop snuck into the depths of the old cathedral where he found Diablo's soulstone and shattered it.
Partially free, Diablo immediately sought to find a host powerful enough for him to use and decided that Leoric was the perfect candidate of all the townspeople above. Diablo was very weakened from his long imprisonment however, and so sought to slowly break down Leoric's mind. The process lasted for four years and slowly but surely drove Leoric mad. When Diablo made his final attempt to seize control of Leoric though, he noticed that the king, although ravaged and but a shell of his former self, still possessed a lingering spirit which Diablo could not overcome. Dismayed, he released his hold over Leoric and instructed Lazarus to bring him the young prince Albrecht instead. Lazarus abducted the boy and brought him down into the deepest level of the labyrinth.
At this time Aidan, brother of Albrecht and eldest son of Leoric, returned to Tristram to find it in shambles, his father dead and his brother abducted. He was a warrior of great prowess, and he journeyed into the labyrinth to find his brother and stop the evil that had beseiged their town. Diablo took notice of him during his slow descent and began to infiltrate his mind, hoping to make Aidan his host rather than the younger Albrecht. As Aidan reached the bottom he slew Diablo who had possessed his brother. But Diablo had convinced the warrior that the evil could only be contained if he joined himself with the soulstone. Aidan jammed the prison into his forehead.
Finally in possession of a strong host, Diablo could now leave Tristram.
 Diablo II
As Diablo left Tristram he began to journey east towards the desert of Aranoch and the Tomb of Tal Rasha, where his brother Baal had been buried and hidden. On his way he destroys Tristram and the Rogue Monastery, where he summons Andariel to stand guard against any pursuers. Before he makes his way into the desert inn, he finds Marius, a survivor on the attack on the monastery, and Marius inexplicably joins Diablo on his journey.
As they enter the final chamber in the Tomb of Tal Rasha, Tyrael encounters them. He is there to prevent Diablo from freeing Baal and the two engage in battle. Though Tyrael appears to be winning, Marius inadvertently frees Baal during the fight, and the two Prime Evils together overwhelm Tyrael and summon Duriel, another Lesser Evil, to guard the angel.
The two continue to travel towards Kurast where their eldest brother Mephisto was imprisoned. However, Mephisto had already freed himself, possessed Sankekur and taken control of the entire Zakarum. Once the three brothers unite there, they combine their powers to open a portal to the Burning Hells. As the portal opens, Diablo sheds himself of his mortal host body and assumes his demonic form. Afterwards Diablo alone steps through the portal to "send forth his terror into Hell" in order to once again rally the forces of the Burning Hells behind the Prime Evils, while Mephisto and Baal both remain on Sanctuary.
In Hell he is later defeated, and shortly thereafter his soulstone is shattered at the Hellforge.
 Diablo III
After Tyrael, Leah, Adria and the Nephalem confined the essence of Belial and Azmodan in the Black Soulstone, it was revealed that Adria had been Diablo's agent from the beginning, and that everything she had done up to this point was part of her plan to resurrect him. She also revealed that Leah's father is Diablo, making her the perfect vessel for his physical form. Using Leah as a sacrifice, Adria resurrected Diablo. However, now having the souls of all the Lords of Hell within him, Diablo became the Prime Evil, the most powerful demon in existence. Diablo then began his assault on the High Heavens, the defending angels being no match for him.
Tyrael and the nephalem follow Diablo to the High Heavens, where the city is under attack. The defending Angels warned the nephalem that Diablo was attempting to reach the Crystal Arch, which is the source of all of the angels' power. If Diablo corrupted the Crystal Arch, his victory over the High Heavens would be complete. The nephalem then encountered Diablo at the top of the Crystal Arch. After the long brutal battle they eventually defeat Diablo, destroying his physical form.
 Current Whereabouts
Diablo's ultimate fate is unknown. His corpse is seen disintegrating as it is sent falling, but the Black Soulstone is still intact. It is left to wonder if Diablo's essence has merely been confined to it again, and the whereabouts of the Black Soulstone itself is now unknown.
 Physical Appearance
In Diablo I, he appears as a giant humanoid demon with red skin, claws on both hands and feet and a multitude of spikes protruding from his back and head.
In Diablo II, his appearance changed a bit. When the player encounter him in Hell the second time around, he has grown a tail (coupled with more spikes) and his features are slightly more animal-like. His movement has also become more beastlike; in Diablo 1 he walked upright, whereas in Diablo II he not only walks upright but also runs on all four. He is commonly referred to as "Dino Diablo" in this form by fans.
In Diablo III, his appearance changed a lot. He appears to be very skinny, which is contrary to his previous, giant and lizard-like forms. He features four arms, of which the top two have some kind of blade-like extensions. The shoulders are big and they have a mouth on each of them, which has become a recognizable feature among the fans. His tail and his legs are very similar to those of the Diablo II version, with spikes covering them.
Diablo also makes several appearances in The Sin War trilogy and Kingdom of Shadow. In all of them, he appears wildly different from the games, generally described as a shapeless entity who uses the fears and terrors of others to appear as hellish as possible in the eyes of his beholders. Some features still remain the same in the books though, such as the iconic ram's horns, taloned feet, sharp teeth and taloned fists.
 Powers and Abilities
As the Lord of Terror, Diablo's greatest power lies within utilizing his enemies' fears. He rules over his demon servants through his sheer ability of terror, and to most he is the most terrifying being of all. Few demons can stand the vision of his true form, as evidenced by Astrogha who "shivered for years" after seeing it.
Diablo is capable of taking on almost any shape, whatever suits him best at the time in order to instill the most fear in his enemies. Diablo relishes this fear, and enjoys terrorizing his enemies as an artist enjoys his work.
In terms of physical strength, Diablo is the strongest of the Three and as such the strongest known demon, although he prefers to avoid direct contact if it is possible and rather likes to work from behind the scenes. He controls the powers of fire with ease, and can literally rain hell down on his enemies if the situation calls for it.
- Astrogha is a giant and intelligent arachnid demon who was Diablo's chosen representative in the Triune cult during the Sin War.
- Assur was a demon general blessed by Diablo to be near impervious to damage.
- Na-krul, a powerful commander of Diablos army before he was exiled for his treason against Hell, was the main antagonist of the Diablo: Hellfire expansion set.
In Diablo II, Diablo was voiced by Bill Roper, who also provided the voice for Ogden the Tavern Keeper and Diablo in Diablo I, and Hadriel in Diablo II. For Diablo III, the voice is provided by J.B. Blanc.
 Official Art
Diablo, as he appears in the Diablo III Act IV Cinematic.
Diablo, as he appears in the Diablo III Act IV Cinematic
Diablo in the the Diablo III teaser trailer.
In-game Diablo in Diablo III.
Final game screen in Diablo III.
Concept art of Diablo in Diablo III.
Cover of the Diablo Archive.
Diablo's page in the Book of Cain.
Diablo in a Diablo I cinematic
Diablo in Diablo I.
Diablo in Diablo II.
 Fan Art
- Cain, Deckard., Book of Cain, page 23.
- Knaak, Richard A., The Veiled Prophet, page 191.
- Knaak, Richard A., The Veiled Prophet, page 191.
- 2011 Blizzcon - Diablo 3 - Lore Panel, 18:00 - 19:13
- 2011 Blizzcon - Diablo 3 - Lore Panel, 28:26 - 28:36
- Knaak, Richard A., Scales of the Serpent, page 74.
- Knaak, Richard A., Scales of the Serpent, page 75.
- Cain, Deckard., Book of Cain, page 23.
|Prime Evils||Baal • Diablo • Mephisto|
|Lesser Evils||Andariel • Azmodan • Belial • Duriel|
|Notable Demons||Assur • Astrogha • Gulag • Thonos • Kabraxis • Lilith • Lucion • Xazax|