Demons are bloodthirsty, vicious monsters who only care about being more powerful than the ones they deem weak. Unlike the angel's order and discipline, demons are rampant and unorganized. In battle, they relentlessly attack their enemies with brute force. Some are very small like Imps, or very large like Seigebreaker Assault Beasts. Demons usually use claws, talons, or fangs to rip apart enemies during battle. Demons can also sustain a large amount of pain and wounds before dying. Demons, unlike angels, are physical beings, and when they die stay where they are. Demon's blood are strange colors, like purple, green, and orange. It is also important to note that Undead are not demons.
Presence in Sanctuary
Demons cannot exist naturally in Sanctuary and must be summoned through a magical ritual. Their spirits cannot usually manifest itself, so they require mortal hosts in order to take shape. Dark Cultists often summon up demons from the Burning Hells to serve them in battle. Thralls, after killed, are banished back to Hell after they have been defeated.
The Sin War
During the Sin War, when Mephisto and the renegade angel Inarius sought to lure man to the forces of dark and light, demons battled the High Heavens relentlessly to gain control. This kept on until Uldyssian made the factions have a brief truce, for the sake of humanity.
During the events of Diablo I, when the Lord of Terror had possessed the King of Tristram, Leoric, demons were attacking the small town and hopefully to gain entrance to the Tristram Cathedral. He then later gains control of Prince Albrecht, after Archbishop Lazarus impales him with Diablo's soulstone. Diablo then summons countless hordes of demons, making the town a outpost for the Demonic Legion. He doesn't stop there, and summons demons to attack the town, as well as freeing his brothers, Baal and Mephisto. The hero then fights his way through the hordes until he reaches the cathedral. There, he kills the rest of the demons and traps Diablo by shoving the soulstone of Diablo into his forehead.
In Diablo II, the Dark Wanderer leads a group of demons upon a tavern, in which Marius, the narrator of the story sees and decides to follow him. Diablo leaves "footprints" of demons to stop the group of heroes trying to find and kill him. He also enlists two Lesser Evils, Duriel and Andariel, to protect him from the group. When Baal is freed, Diablo begins to wrest control of Sanctuary.Sescheron. He kills a barbarian guarding it, and the demons storm the fortress and raze it. He continues to lead his army on a murderous rampage across the land to Mount Arreat, and lays seige to Harrogath. The Lord of Destruction leads his army into the mountain, where he hopes to corrupt the Worldstone and end the Great Conflict.
Twenty years after the destruction of the Worldstone, Sanctuary is preparing for a full out invasion from the Burning Hells. But it never happened, attracting the intrest of Deckard Cain to find out why. Belial, the Lord of Lies, leads his Dark Coven and a portion of the Demonic Legion and beseiges Caldeum. Belial is later killed and trapped in the Black Soulstone by a group of nephalem. Azmodan, the Lord of Sin, then realizes the power of the Black Soulstone and breaks the Demonic Legion from Arreat Crater to obtain it. He is later thwarted by the same group of nephalem that killed Belial. The victory is short lives because Adria the Witch is revealed that Leah, her daughter, is also the daughter of Diablo. Adria then absorbs the Black Soulstone into Leah, and she open a portal to Heaven. Diablo, now the Prime Evil, then proceeds to wound Archangel Imperius and destroy the Diamond Gates, leading the full force of the Demonic Legion into the Silver City. Diablo is killed later by the group of nephalem, ending the Great Conflict forever.
HistoryDemons originate from the Black Abyss or are spawned within the Hells themselves. It is not known how the first demons came into being, but it is revealed that other entities - even humans - can eventually become demons (see the Goatman article for instance). Demons have been in creation ever since Tathamet was killed and his body became the foundation for Hell. Demons are enlisted in the Demonic Legion, serving their masters with a bloodthirsty appetite for battle and blood. The demonic armies usually greatly outnumber the opposing force, but are very unorginized because of their bloodthirsty behavior.
PowersMost demons can only use weapons to fight, but other demons, like Demonic Hell-Bearers, can scale walls and spew out more forces to combat enemies. Many larger demons are used to decimate forces so smaller troops can get into enemy lines. Demons like The Butcher are very skilled in different weapons, such as chains or swords. Some demons, like Serpent Magi, are gifted in magic and can teleport and cast spells.
The Great Evils are manifestations of the beast Tathamet, and they lead demons into battle against the High Heavens. The Triune worships these demons as gods, along with the Dark Coven. The evils can only be killed if they are trapped in a soulstone and it is smashed. There are seven evils in all, the three Prime Evils and the four Lesser Evils.
The Prime Evils
Commonly known as "The Three", they were the most powerful demons in Hell until the Dark Exile. Mephisto is the oldest brother, followed by Baal, and then the most powerful, Diablo.
- Diablo, Lord of Terror - Youngest of the Evils but the most powerful
- Mephisto, Lord of Hatred - Eldest of the Three
- Baal, Lord of Destruction - Middle brother, demons he leads are more stupid than his brothers'
The Lesser Evils
These evils are very powerful, but not as powerful as the Prime Evils. They were the demons who revolted against the Prime Evils and banished them to Sanctuary during the Dark Exile.
- Azmodan, Lord of Sin - Greatest military tactician in the Burning Hells, last Evil to be trapped in the Black Soulstone
- Belial, Lord of Lies - Likes to hide in the shadows, beseiges Caldeum until a group of nephalem kill him
- Duriel, Lord of Pain - Has the appearence of a bug, killed by a group of heroes
- Andariel, Maiden of Anguish - Sided with Diablo to protect him from the heroes, killed shortly after
Some demons have plotted to overthrow the Great Evils, like Lilith and Kabraxis. Neither were successful.
The Khazra, or "Goatmen" are a lesser form of demon. They were once human, until the powerful Vizjerei turned them into satyrs during the Mage Clan Wars. They now serve under the seven lords of Hell, and inhabit many areas around New Tristram. Some Khazra, like Serpent Magi, are gifted in magic and the spiritual arts.
There are no ranks in Hell, except for the Great Evils. However, there are many important demons worth mentioning.
- Assur - Leader of demons in Demonsbane, Diablo's favorite
- Astrogha - Fought in the Sin War
- Gulag - Servant of Baal; killed by Uldyssian
- Lilith - Daughter of the Prime Evil Mephisto and brother of the demon Lucion. Led demon rebels into the void and created Sanctuary with the Worldstone. Mother of the Nephalem.
- Lucion - Son of Mephisto and brother of Lilith. led the Triune into the world and was killed by Uldyssian
- Xazax - Transforms an army of mortals into demons. Diablo kills him because of his power.
- Thonos - Summoned by Lilith to kill Achilios and Uldyssian, killed by Achilios
- Hephasto - Works at the Hellforge
- Kabraxis - Extreamly powerful demon; rivaled the Three
- Shenk - Commander of Baal's seige of Sescheron