The Warp Ghosts are a Renegade Chapter of Chaos Space Marines of unknown Founding and origin, whose survivors now serve Chaos Undivided. It is unknown exactly when the Chapter betrayed the Imperium of Man and turned to Chaos, but recently the Warp Ghosts have allied themselves with Abaddon's 13th Black Crusade. Being only a single Renegade Chapter, the Warp Ghosts have far fewer Chaos Space Marines and equipment than the original Traitor Legions, but are still renowned for their ferocity among the Forces of Chaos. The Bleak Brotherhood is believed to be a faction or warband of the Warp Ghosts. It is believed that the Warp Ghosts, or at least a sizable faction of their number, have recently joined their forces to the 13th Black Crusade of Abaddon the Despoiler, although doubtless such a loyalty will last only so long as their price is met.
The sinister legend that surrounds the Warp Ghosts is well known among the students of the profane, but itself has been the cause of considerable confusion as to the attribution of their actions and involvement in various wars and incursions down the millennia. The Warp Ghosts themselves are believed to be a sizable force, perhaps numbering several thousand damned Chaos Astartes at their core. Their true strength, however, lies in the possession of at least two score of powerful warships, ranging in power from fast raider vessels to vast Grand Cruisers. Their flagship, it is claimed, is a Heresy-era assault barque of prodigious size known as the Spectre Ens, while xenos gunships, stolen Imperial troop macro-transports and even a nightmare-conglomerated Space Hulk are attested as under their control, according to unconfirmed reports.
As well as marauders and world-breakers in their own right, the Warp Ghosts are also renowned as mercenaries among the dark forces of the Eye of Terror and far beyond, owing fealty to neither god nor master but only to the coin of strong flesh and blood, fealty and sacrifice. Theirs, it is said, is a singular curse, to be condemned as withered undying souls, damned for some unknown sin or treachery, to ride the tides of the Warp in search of new flesh to wear, as any body that they invade is itself quick to spoil and ruined by their tainted possession. Condemned to wander the tides of the Warp, they have gained a reputation as the ferrymen of the damned, transporting vast war hosts of mutants and Renegades as well as Chaos Space Marine warbands and the forces of the Dark Mechanicus to ravage the stars, so long as their sinister price is met. These dark proclivities have led the Warp Ghosts and their nature to be confused in garbled after-battle reports with other Chaos forces they have carried to war, such as the Deathmongers, the Bleak Brotherhood and the Unhallowed, while they have also been known to have made common cause with Fabius Bile and his abominations on more than once occasion.
- The Martyred Sons (416.M37) - Inquisitor-Lord Antonius Coil of the Ordo Malleus discovers the current location of the nomadic Hell-Forge of Sarum while conducting an Exterminatus against the Warp-tainted Hive World of Goleonda IX, and moves to see it destroyed at last. Along with warships committed from Battlefleet Reductus and several Militarum Tempestus regiments, he mobilized the aid of three Space Marine Chapters, the Sons of the Raven, Celestial Guard and the Brazen Claws, to strike deep into the perilous Golgotha Wastes against this nightmarish thorn in the Imperium's side. Within sight of the baleful world, the Imperial fleet is ambushed on all sides by the pale warships of the Warp Ghosts and corrupted Black Wings Chaos Space Marines and the horrific Daemon Engines of their Dark Mechanicus allies of Sarum. In the brutal seventeen-solar-hour void battle that follows, the Imperial fleet is encircled and slowly torn to pieces both from without and from within as Daemons rip open passages into realspace deep onboard the stalwart vessels. Only the Chapter fleet of the Brazen Claws breaks free from the trap without crippling losses, while the human contingent of the Imperium's strike forces are annihilated to the last. The ravaged Celestial Guard Chapter will take nearly a standard century to rebuild from its grievous losses from its stores of gene-seed, swearing bitter vengeance against the Warp Ghosts. The fleet-based Sons of the Raven Chapter, not one of whose Battle-Brothers escaped the deadly trap, are declared martyred and the great Bell of Lost Souls in the Tower of Heroes on Terra tolls to mourn their passing. Eighteen standard years later, a corrupted Warspite-class Battle-Barge, believed once to have been the Seraphina Carricus of the Sons of the Raven Chapter, is encountered transporting a Warp Ghosts raiding force off Mezoa XV, the withered face of Jo'sun Hernezu, the martyred Chapter's last Master, worn by its revenant captain.
- The 13th Black Crusade (999.M41) - It is believed that the Warp Ghosts, or at lest a sizable faction of their number, have recently joined their forces to the 13th Black Crusade of Abaddon the Despoiler, although doubtless such a loyalty will last only so long as their price is met.
- Stygian Vanguard - Such mystery surrounds the Renegade Astartes known as the Warp Ghosts that barely a handful of confirmed depictions of their war machines exist in the archives of the Ordo Malleus. These fragments of forbidden knowledge have been pieced together by the toil of several generations of indentured Imperial savants to form a tenuous description of a cadre of siege engines within the group. This formation has been dubbed the "Stygian Vanguard" by Ordo Malleus Inquisitors and has been engaged by the forces of the Grey Knights on four different occasions, and the Exorcists and Revilers Chapters in an unknown number of encounters. The Stygian Vanguard is thought to represent a gathering of the Warp Ghosts' entire heavy tank and siege capacity into a single battlefield formation, and is thought to include amongst its ranks several dozen Vindicators and Predators in addition to a Typhon Heavy Siege Tank. The Stygian Vanguard is said to possess certain characteristics beyond those normally encountered even among the hosts of the hell-tainted Ruinous Powers. Its attacks are invariably heralded by abnormal atmospheric phenomena, including the sudden appearance of unnatural mists, the falling of night during daytime, strange lights in the sky and a deep, haunting clarion call rolling across the land from no discernible source. Thus cut off, Imperial bastions and fortress-cities find all Vox systems mysteriously silent, and allied formations ignorant of their plight. The first, and invariably last, sight the defenders see is a sudden parting of the lambent mists as the Stygian Vanguard descends upon them, large bore guns raining death and destruction upon them. Even the staunchest of defences cannot hold against such a sudden and relentless assault, and it is believed the mightiest of fortifications will come crashing down under their weapons fire. In the wake of the Stygian Vanguard comes the ground troops of the Warp Ghosts, though in truth very few defenders have survived to describe them, or if they have, their maddened ravings can hardly be counted as reliable.
Based on their colour scheme, the Warp Ghosts may be another name for the Death Mongers, a similar Chaos Space Marine warband. Or, this duplication of colour scheme may simply be an oversight on the part of Games Workshop.
The Warp Ghosts' original Loyalist Chapter colours were dark green and white with black and gold details. After turning to Chaos, their armour became the pale green of rotting flesh with black trim.
The Warp Ghosts Chapter badge is currently unknown. However, iconography known to have been deployed by Warp Ghosts' assets that has been only rarely witnessed depicts two skulls facing away from one another. A small black Octed (eight-pointed Star of Chaos) is centered upon the twin skulls. Ordo Malleus diabolists theorise that this symbol represents a stylised coin, the skull face looking in two directions at once. They note commonalities with certain legends of the Hellan cultures of Ancient Terra, as well as the role the Warp Ghosts are said to play in the ranks of the servants of the Ruinous Powers. It is currently a matter of debate whether this symbol is unique to a certain war machine, the icon of the Stygian Vanguard, or of wider significance to the Warp Ghosts as a whole. The Warp Ghosts are also known to adorn their Power Armour with the usual heretical symbols of devotion to Chaos, such as the eight-pointed Chaos Star.
- Codex: Eye of Terror (3rd Edition)
- Codex: Chaos Space Marines (4th Edition), pg. 18
- Codex: Chaos Space Marines (3rd Edition, 2nd Codex), pg. 76
- Imperial Armour Volume Thirteen - War Machines of the Lost and the Damned, pp. 56, 64-65