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. 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. Since then, Doombreed has continued to serve Khorne well. During the 31st Millennium, he fought for his master at the side of Horus during the Horus Heresy, and was aboard the Warmaster's flagship Vengeful Spirit when Horus was slain and the Emperor mortally wounded at the Battle of Terra. Over the millennia he has returned to plague humanity countless times.
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 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 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 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.
- 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 Chaotic 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.
- Black Legion (Codex Chaos Space Marines Supplement), pp. 34, 76
- Codex: Chaos (2nd Edition), pp. 139-140
- Codex: Chaos Space Marines (4th Edition)
- Liber Chaotica: Khorne, pg. 84