Usually, these winged and clawed creatures can be summoned in the same nature as other Chaos daemons. Furies are amongst the lowliest denizens of the Realm of Chaos, making their home in the Formless Wastes that lie outside the domains of the Ruinous Powers.
It is said amongst Imperial savants of the Inquisition particularly versed in the dark secrets of daemonology that Furies are actually created from the souls of those Humans and other sentient beings who selfishly served Chaos for their own personal gain, rather than devoting themselves heart and soul to a single Chaos God.
When they finally fall or die in battle, no Chaos God will claim them, and their tragic fate means they can never enter any of the Ruinous Powers' personal kingdoms within the Realm of Chaos.
They are doomed to spend eternity in a grotesque, gargoyle-like state, drifting like a leaf through the chaotic eddies of the Immaterium, forever exposed to its unpredictable nature. Such is the punishment for indecisiveness and selfishness amongst the Dark Gods.
The only respite from this fate for a Fury are the rare daemonic incursions into realspace which allows them to vent their impotent wrath upon unfortunate mortals.
Somewhat larger than a man, with a hunched posture, Furies are hideous winged daemonic creatures. They have bestial, long-jawed faces and mouths full of jutting teeth and fangs. A bristly mane of black hair runs from their short horns to the base of the spine, while two broad batwings sprout from the shoulders. Their colouration varies with the flow of the Warp or the daemonic powers currently ascendant, but black and red tones seem most common.
Because they serve no patron Chaos God, Furies rank very low in the daemonic hierarchy of Chaos. However, their leathery, bat-like wings allow them to strike swiftly and from above, which gives them an advantage over many more powerful Lesser Daemons and Daemonic Beasts and makes them an asset for any daemonic force.
When on the hunt, Furies keep to the air, looking to ambush their target by attacking from above. Cowardly by nature, due to their status at the bottom of the daemonic hierarchy, Furies prefer to hunt those who venture alone, are wounded or injured, or otherwise look to be unable to fully defend themselves. Dropping down on outspread wings and uttering bone-chilling howls, the Furies attack in swarms, seeking to rend their targets limb from limb.
As Furies constantly seek respite from their eternal torment, they are especially watchful for weakness in the walls between the worlds. Thus, Furies are often one of the first daemons to appear near an open Warp Gate or when Gellar Fields begin to flicker and fail.
When they appear in realspace, Furies are quick to find mortals to vent their rage upon. Gathering in large packs, they slaughter all they can find in a vain attempt to appease their inner hunger for a sense of purpose amid the roiling and uncaring waves of the warp.
While individual Furies can be defeated by a man who holds to his faith in the Emperor and stands his ground (and is well-armed), and hunting flocks may be repelled by sufficient firepower, Furies found in the service of Greater Daemons are a different matter.
Driven by a combination of fear and awe, these Furies attack with enthusiastic viciousness, looking to gain favour in the eyes of their daemonic betters. It is also rumoured that in these cases they often have a purpose beyond simple death and destruction, and may even seek to capture specific individuals or items in order to present them to their daemonic commanders.
In the Service of the Dark Gods
Furies are easily subjugated by the Dark Gods when they desire these creatures to fight alongside their armies in realspace or the Warp. In such cases, the unformed wastelands of the Immaterium are swept with the sentience of one or another of the Ruinous Powers, and any Furies that might be hunting there are collected.
Transported to the Chaos God's domain, the Furies' appearance shifts to reflect the vast intellect that now guides their actions. Those in thrall to Khorne are typically red-skinned and wrathful, whilst those subsumed by Nurgle exude disease and corruption, their bodies hardened by Warp boils and congealed ooze from weeping sores.
How Furies fight as part of a daemonic legion, and how many do so, varies. Lords of Change make the most frequent use of Fury flocks, creating aerial wings that shimmer above the capering masses, often screening the presence of Screamers behind their flapping wings.
In Nurgle's Plague Legions they tend to fly ahead of the Tallybands, seeking to consume meat while it is still fresh, while they move in the wake of the armies of Khorne, picking apart the carrion-feast left behind by the Blood God's daemonic cohorts.
Without specific commands, flocks of Furies circle above a battlefield like vultures, waiting for any hint of weakness. As with some scavengers in realspace, the Crows of Chaos can sense fear and smell weakness, and will generally only attack wounded, isolated or fleeing targets.
Enemies brave enough to stand their ground often find they can dissuade the Furies, causing the screeching daemons to break off their dive in search of easier prey. Those who cower or lack the strength to continue fighting are not so lucky, and are fallen upon with deadly claws that hook and tear their prey apart in a flurry of violence.
Even in triumph, Furies rarely survive a single battle, for as they sate their hunger upon the fallen, the very daemons that fought alongside them often turn upon their former allies.
Even those Bloodthirsters that find the flocks most useful in battle occasionally grow disgusted with their cowardly actions, and will order the Lesser Daemons of Khorne to massacre every last one of the carrion-feeders. After all, there is no end to the Formless Wastes, nor the wretched creatures that inhabit it.
Mortal servants of Chaos have also been known to attempt to summon and enslave Furies. Their great mobility, horrifying visage, and relative weakness make them a popular summoning choice for heretical worshippers seeking power.
Various Chaos Cults in the Koronus Expanse are known to have used Furies for a variety of purposes, the most common being simply sending the daemon out to cause death and destruction, be that on a planet or inside a vessel. Most of these sad practitioners find however, to their dismay, that even the weakest of daemons is more than a match for a deluded mortal.
On rare occasions, a pack of Furies will become trapped in realspace, cut off from the Warp and the terrible realm which sustains their existence. Usually in such cases the creatures would simply fade, screaming, into nothingness.
When caught outside the Warp in the strange currents and eddies of the Screaming Vortex, however, something entirely inexplicable happens. In these rare cases, the pack of daemons slowly begins to wither and atrophy, their Warp-infused bodies losing their vitality, yet they still live on, tormented by their separation from the Warp but unable to simply vanish from existence.
The only means by which the swarm of gargoyle-like beings may remain in existence is by feasting on the misery, pain, and torment of mortal souls. As such, these swarms of creatures from the nether seek out groups of living beings in desperate attacks.
In combat these creatures are frenzied, driven mad by their metaphysical hunger and without heed of their own safety. They swarm as one, seeming to possess a single mind born of their desolation and consuming need to inflict agony. A blur of fang and claw, the swarm of Warp-spawn tear their victims to pieces, flaying flesh from bone and gorging themselves on the resultant fear and torment.
Eventually these horrors, shrivelled and wizened, will cease to exist entirely, their forms devoured by the exertion of remaining in realspace.
Should the nether swarm find a suitable locale to inhabit, where their depredations may continue unhindered indefinitely, this dissolution may take standard years to come to pass -- though it is inevitable, as no amount of pain and agony inflicted can ever fully restore these vile creatures to full existence.
- Black Crusade: Core Rulebook (RPG), pg. 351
- Codex: Chaos Daemons (8th Edition), pp. 70, 113
- Codex: Chaos Daemons (4th Edition), pg. 46
- Codex: Chaos Space Marines (3rd Edition, 2nd Codex)
- Rogue Trader: The Koronus Bestiary (RPG), pg.120