Doombreed takes the form of a giant Bloodthirster, a Greater Daemon of the Blood God, eternally wreathed in black smoke which slowly transforms into red-hued muscle as his form grows ever larger with each life he takes.
Hooved and winged, his teeth are the size of Human blades and scraps of flayed fur and skin hang from his dripping, hound-like muzzle.
Doombreed was one of the first human beings ever raised to daemonhood by the will of Khorne. His True Name has long been forgotten, but he was once a mortal human. Centuries before the Age of the Imperium began, Doombreed had been a human warlord on Old Earth some time in the 1st or 2nd Millennium.
He carried out a campaign of such wanton slaughter and sheer genocide across the breadth of Mankind's homeworld in that forgotten time that Khorne, then still a relatively young Chaos God, found him to be worthy of the ultimate reward of daemonhood as one of the first of the Blood God's Daemon Princes. He has served his master well over the millennia, and has returned time and time again to plague humanity and all those that would stand against the will of the Blood God.
In the early 31st Millennium, the Daemon Prince fought at the side of the Warmaster Horus during the Horus Heresy. When Accazzar-Beta refused to pay fealty to Horus, the Warmaster led an attack on the world that served as a sacrifice to summon Doombreed.
Manifesting from a red pearl, Doombreed slaughtered the entire planet's population while the Traitor Legion forces withdrew. Argonis, a Herald of the Sons of Horus Legion brought to the surface by Horus to witness the summoning of Doombreed, ensured Accazzar-Beta would live forever as an example of the "Dark Compliance" that would befall any world that resisted accepting Horus as its new Emperor.
Years later, Doombreed was aboard Horus' flagship Vengeful Spirit when the Warmaster was slain and the Emperor was mortally wounded at the climax of the Battle of Terra. Doombreed fought alongside the Greater Daemon of Slaanesh N'Kari against the Emperor and His companions as they sought out Horus' throne room.
Although he vowed never to allow others to learn it once he realised to which Daemon it belonged, Ctesias used it to summon Doombreed to Sortiarius, the Planet of the Sorcerers in the Eye of Terror, when Ahzek Ahriman returned for the first time since his exile in an attempt to undo the horrific effects of the Rubric of Ahriman upon his Legion's Rubric Marines.
In the resulting Battle of Sortiarius, Doombreed claimed the "skull" of the Daemon-possessed Warlord-class Titan Czetherrtihor in single combat, raising it up as a sacrificial offering to Khorne.
5th Black Crusade
During the 5th Black Crusade in 723.M36, Abaddon the Despoiler and the Forces of Chaos scoured the Elysia Sector, raiding hundreds of worlds and causing untold death and destruction. It was Abaddon's intention to create a sector-wide conflict that would provoke a massive response from the Imperium and draw in Chapters of the Adeptus Astartes.
His plans set in motion, the Warmaster of Chaos led the bulk of his Black Legion to the city of Kasyr Lutien on Tarinth, burning the great metropolis to the ground and enslaving its people. When the Warhawks and Venerators Space Marines arrived on Tarinth in full Chapter-size strength, they made an immediate assault upon Kasyr Lutien.
At the same moment, Abaddon ordered the mass sacrifice of ten million Imperial citizens. Their blood was funnelled via the city's great canals into a vast lake of gore. Above the lake, a rift into the Warp cracked open and Doombreed stepped into reality, howling in triumph.
Abaddon had made a dark pact with Doombreed, promising it the skulls of an entire Chapter of Space Marines in return for its service. With thousands of Bloodletters pouring forth from the lake of blood, Doombreed waded into the ranks of the Warhawks and Venerators. The Black Legion then sprang their own trap, and from prepared positions across the city, they opened fire on the Loyalists, blocking their retreat.
Though they fought without fear or respite, both Chapters fell that day, their warriors mutilated by the daemonic host and their gene-seed forever lost to the Imperium. The skulls of the fallen Space Marines were taken by Doombreed to be mounted upon the mighty throne of the Blood God.
Eclipse of Hope
Five thousand Terran years after its disappearance, the warship Eclipse of Hope, now a Space Hulk, was encountered by Mephiston, the Chief Librarian of the Blood Angels Chapter, in the late 41st Millennium. What he found aboard it led him to the world of Pallevon. There, he and the Blood Angels who accompanied him discovered a perfect sculpture of their Primarch Sanguinius in gold, silver and ruby that captured the moment of his death at Horus' hands aboard the Vengeful Spirit.
Only Mephiston among the Blood Angels party believed the statue to actually be a corrupted artefact of Chaos and sought to destroy it, but his attempt released Doombreed from an imprisonment that had lasted for five millennia. Mephiston and Doombreed fought as the Daemon Prince sought to turn the Lord of Death to the service of the Blood God. Doombreed failed and the Librarian banished Doombreed back to the Warp, but the Daemon Prince was now free to cause mayhem across the galaxy once more.
Time of Ending
By 999.M41 during the 13th Black Crusade of Abaddon the Despoiler, Doombreed had rejoined the forces of the Warmaster of Chaos and took a prominent role in the battles of that desperate conflict.
Later, in the years after the formation of the Great Rift, Doombreed was at the forefront of the Blood Crusade initiated by the Blood Legions of Khorne's daemons which swept across much of the galaxy.
- Chaos Armour - Doombreed wears brazen armour which bears the Mark of Khorne. This armour is a living part of the Daemon Prince, and it is sustained by its own unquenchable inner Warp energies. This armour cannot be negated by Force Weapons or psychic attacks, which gives Doombreed an advantage against psychic force weapons compared with other daemons.
- Axe of Khorne - In his right hand, Doombreed carries a mighty Axe of Khorne, suffused with Chaos energies and laden with death. Some of the rare survivors of an encounter with such a fell weapon report that its power comes from the burning abhorrence of another daemonic servant of Khorne bound within it.
- Rod of Khorne - In his left hand, Doombreed carries the Rod of Khorne, a huge staff made of twisted bone that bears the Mark of Khorne at its head. Khorne hates all users of magic or psychic power, and his Rod is a deathly bane to all such practitioners of the sorcerous arts.
- Collar of Khorne - The Collar of Khorne that hangs around Doombreed's neck is said to be forged from the heat of Khorne's rage at the very foot of the Blood God's throne of brass. The power of the collar is to suck the energy of the Warp from around it, fortifying the wearer and also protecting it from psychic attack. As a result, no force weapon can harm the wearer and psychic attacks that effect the wearer are nullified and will not work.
- Ahriman: Unchanged (Novel) by John French, Ch. 20
- Black Legion - A Codex: Chaos Space Marines Supplement (6th Edition), pp. 34, 76
- Codex: Chaos (2nd Edition), pp. 139-140
- Codex: Chaos Space Marines (4th Edition), pg. 32
- Dark Compliance (Audio Book) by John French
- Eclipse of Hope (Short Story) by David Annadale
- Liber Chaotica: Khorne, pg. 84
- Mephiston: Lord of Death (Novella) by David Annandale, Chs. 4, 8-9
- Warhammer 40,000: Rulebook (8th Edition), pg. 167