The Devourers were the premier cadre within the World Eaters Legion that served as a dedicated bodyguard unit for their Primarch Angron during the Great Crusade and the Horus Heresy eras of the late 30th and early 31st Millenniums. In battle the Devourers fought encased in Terminator Armour and carried the most savage weapons the XIIth Legion possessed. This warrior band had only twelve members, and access to its ranks was only attained by defeating another Devourer in single combat to the death or, should one of its number fall in battle against an enemy, a successor was selected by a contest open to all of the Astartes in the World Eaters Legion, only one of whom would survive.
When the War Hounds were reunited with their Primarch Angron, the XIIth Legion was soon influenced by Angron's Nucerian cultural beliefs and blood rites that would become an important part of the World Eaters' core beliefs. Under Angron's leadership, the culture within the XIIth Legion shifted to ever more violent and bloodthirsty mores and values. These became quickly echoed in the shifting skein of the Legion's own rites and ceremonies, whose former nature disappeared altogether and was replaced by Angron's own bloody code of butchery and savage competition. Trial by combat quickly became the XIIth Legion's preferred route to settle disagreements within its ranks, and bloodletting by warriors in open discord was an honourable thing both in Angron's eyes and that of his Legion. In such trials could a World Eater of higher rank be challenged for the right to command, although such rare contests were always to the death. The most revered measure of this latter practice was the trial to earn membership in the elite Devourers.
In the wake of the sweeping changes instituted by Angron within the XIIth Legion, the elite unit known as the Devourers was formed in honour of their lord. This cadre consisted of a dozen Legionaries. Access to its vaunted ranks was achieved through single-combat to the death within the World Eaters' fighting pits. If a Devourer was slain in battle against a foe, a contest open to all Legionaries within the World Eaters was held to determine who would be a worthy successor to fulfill the former Devourer's position. Once considered a great honour, over time a position within this cadre was barely acknowledged by the Primarch, as the neural implants known as the Butcher's Nails slowly ravaged Angron's mind, eroded his mental stability and slowly damaged his capacity to reason.
Over a standard century after Angron's return to his Legion, by the time of the Horus Heresy, the Devourers constantly lurked behind their lord, their Primarch hardly sparing them a glance. To be one of Angron’s bodyguards was no longer considered an honour within the XIIth Legion, despite how fiercely the World Eaters’ champions had fought for it in those first, optimistic years. Angron ignored them no matter where they went, never once fighting alongside them in battle. Armoured in their bulky Terminator battle-plate, they never managed to keep up with their liege lord, and they were as prone to losing control to their own Butcher's Nails cortical implants as any other World Eater, meaning any hope of them fighting as an organised unit was a forlorn hope at best. These warriors, who had spent an entire standard century learning to swallow their pride, pretended that they were not actually ignored by the Primarch they were supposed to protect.
In truth, Angron's so-called "bodyguards" annoyed him to no end. His initial acceptance of the cadre of Devourers stemmed from the fact that his brain had not yet been irrevocably damaged by the Butcher's Nails, and he could still understand and appreciate the intention and purpose behind the cadre. The Devourers sought to honour their gene-sire and show him their respect by emulating his gladiatorial origins. Although this initial display of reverence pleased him, Angron disliked the very idea of bodyguards, for their existence implied that he actually needed them. Even their name annoyed him -- "Devourers," as if he had named them himself, as if they were the Legion's finest, although it quickly came to light that none of the Astartes of the XIIth Legion could keep up with their Primarch in the heat of battle. As Angron's sanity slowly eroded away, his initial reason for accepting the Devourers faded, with only his resentment remaining, and he simply ignored his ever-present escort. It was not their fault that they were left behind in every battle, for the uncaring Angron simply rushed forward to sate his bloodlust without any other consideration in his mind, and yet this was seen as a constant failure on the Devourers' part.
Ironically, in the very beginning, the competition to earn a place amongst the ranks of this elite cadre was fierce, but by the time of the Horus Heresy the Devourers were no longer considered the XIIth Legion’s fiercest fighters. Many of the World Eaters' finest warriors refused to challenge for a place in their ranks, for the position was seen as a dishonorable dead end amongst the World Eaters. When asked about joining the Devourers, Angron's Equerry Khârn merely laughed at the sheer absurdity of the proposition. On another occasion, Legion Apothecary Kargos "Bloodspitter" had beaten one of their number in the fighting pits, but instead of honourably slaying the poor bastard, and thus being forced to take his place, the Apothecary humiliated him by sparing his adversary after carving his name into the Devourer’s armour with a Combat Knife out of sheer spite.
Following the end of the Horus Heresy, the World Eaters Legion consumed itself in a bitter internecine conflict that saw it fractured into countless smaller Chaos Space Marine warbands during the Battle of Skalathrax, which had been instigated by Khârn, the former Equerry of Angron and a dedicated Khornate Berserker. In the wake of the XIIth Legion's fracturing, the remaining Devourers either founded their own Khornate warbands as Chaos Lords or joined other warbands as Chaos Champions of Khorne.
- The Horus Heresy - Book One: Betrayal by Alan Bligh, pg. 97
- Betrayer (Novel) by Aaron Dembski-Bowden
- Chosen of Khorne (Audio Short Story) by Anthony Reynolds