Chaos Daemons

A Daemon, also known as a Neverborn amongst the Forces of Chaos, is an intelligent and usually malevolent entity of the Warp that is a living embodiment of Chaos. Daemons are collectively the greatest servants of the Chaos Gods and of Chaos itself as a universal force. They are created at the whim of one of the four major Chaos Gods from a fraction of the god's own power within the Immaterium and act as an extension of his will. A daemon's appearance and intrinsic character reflect the god's own nature. These daemons may be reabsorbed into the god's own psychic signature in the Warp at his whim.

The Chaos Gods are not alone in Warpspace. They have created servants from their own essences -- the creatures that mortals have named daemons based on their ancient legends and religious mythologies -- who are not so closely bound to the Warp. Daemons are entities of a somewhat different nature to their masters, and are the most numerous of the creatures to be found in the Empyrean. A daemon is "born" when a Chaos God expends a portion of its own power to create a separate being. This psychic power binds a collection of senses, thoughts and purposes together, creating a personality and consciousness that can move within the Warp. The Chaos God can reclaim the independence it has given to its daemon children at any time, thus ensuring their loyalty. It is only though the loss of this power that a daemon can truly be destroyed, its mind dissolving into the whirls and currents of Warpspace.

Daemons have no physical presence within the Warp. The Realm of Chaos is anathema to the laws of physics and the starships that navigate its depths do so by taking a skin or bubble of "reality" with them when they enter using their Warp-Drive. Instead of possessing a true physical form, daemons project a form conjured from raw psychic energy that is essentially a lesser interpretation of their master's fundamental nature. Hence, the bizarre and inhuman appearances projected by daemons indicate their presence, status and allegiance to a Chaos God.

Though it may appear to be made of normal matter when it materialises in realspace, a daemon's form is no more physical than it is in the Realm of Chaos. In fact, they are beings of pure Warp energy given shape and depth. When manifested in the material universe, daemons have particular invulnerabilities and weaknesses, as well as many strange powers derived from their Warp-born nature as psychic beings. Slaying a daemon's physical projection does not kill it, but only severs its presence in reality; its true essence in the Warp remains unharmed.

When a daemon is "killed" in the material universe, it is banished back to the Warp. If not simply re-absorbed by its creator, it must remain there to regain its strength that it eventually might manifest itself again. Legend has it that a daemon banished in this way cannot return for a thousand Terran years and a day,, though it is of course impossible to prove such a belief through study, and the concept of time itself is meaningless within the Warp. The slight to a "slain" daemon's pride is considerable, however, and the daemon is forced to endure the mockery of its fellows until it can return to corporeal form and avenge itself. The most powerful daemons will call upon any servants and tributary Lesser Daemons to help them achieve their revenge. If it has many allies, it may also request their aid, though all daemons are cautious in doing so. Such favours must inevitably be returned, and no daemon welcomes the dominion of another creature, be it mortal or daemonic.

Across the stars, Warp Storms rage and the galaxy stands on the precipice of a new age as the 41st Millennium comes to a close. Prophets and augurs proclaim the End Times for Mankind, and the number of instances of daemonic possession across the Imperium of Man is rising. Each psyker so accursed is granted an epiphany; in their last grasping death, the victims glimpse the horrific doom that awaits them -- an abyss of Chaos, absolute in its finality, unending in its despair. Now, across the galaxy, that same vision of ultimate torment -- of an eternity beneath the lash of daemons -- has spread. Across untold star systems, countless life forms read the portents and prepare for the dark days ahead.

Premonitions of disaster are now rife amongst the Imperium of Man, by far the largest of the galaxy's interstellar empires, but few understand the true nature of the Warp and the threat its denizens represent to all life. Yet even distant, technologically-backwards Imperial planets have marked the telltale signs of impending apocalypse -- the proliferation of mutants, the rise of Chaos Cults who worship the Dark Gods and the ever-increasing number of psykers in the human population. The Inquisition sees the warning signs, but there are simply too many Imperial planets in peril for them to halt many of the deadly chain reactions caused by daemonic possession. As psykers implode, small tears in the fabric of reality usher in bloody reigns of terror across thousands of planets, and in their attempts to suppress the truth and forestall mass panic, the Inquisitors adopt ever-more ruthless methods. For every Warp rift sealed though, more holes are opened, and the barrier between reality and the Realm of Chaos is left shattered and gaping in a dozen new locations.

Should the weakness of Mankind prove too great, one only needs to look at the Fall of the Eldar to see the consequences of failure. On their glittering Craftworlds, the remnants of the Eldar race do not need the rune-casting of their Farseers to tell them of the imminent threat. More psychically attuned than humans, each Eldar feels every new rent torn in realspace and cringes. Although utterly self-serving and cruel beyond human measure, even the Dark Eldar shudder at the thought of realspace engulfed by raw Chaos, for if that happened, their hidden city of Commorragh within the Webway would not stay so for long. Even the horrifying alien Tyranids recognize the threat from the Warp -- several Hive Fleets have altered their invasion courses in order to avoid Warp Storms gaping before them. There are scattered records of splinter fleets drifting into Warp rifts, most notably after the near-destruction of Hive Fleet Kraken at the Fall of Iyanden, though the results of such a galactic accident are mercifully hard to catalogue. The Dark Gods care not, for their unknowable plans move apace, and their final victory over the defenders of Creation seems assured.

Daemons in Realspace

GreyKnightsDaemons — The Grey Knights combat a daemonic incursion into realspace

Daemons are a great threat to the peoples of the galaxy, for unlike their masters, they are not wholly confined to the Warp. At the behest of their divine patrons, they work to bring about the day when the barrier between Warpspace and the material dimension is collapsed altogether, allowing Chaos to spill through and the Dark Gods to rule all of Creation. Daemons are the agents of their Chaos God within and beyond this realm, for they are fractions of his will given physical form. Untold billions of daemonic entities make up the host of each of the Chaos Gods. These legions consist of Greater Daemons, Daemon Princes, Lesser Daemons, Daemonic Beasts and other creatures that defy easy classification by mortal savants. Spawned and destroyed by the needs and whims of their divine patron, the size of a Chaos God's forces swells and ebbs with the power he claims over the material dimension at any given time.

Though preoccupied by the machinations of their creators, all daemons lust after the worlds of mortal men. It is on there that the daemons can truly dominate and destroy, conquer and corrupt, for unlike the Realm of Chaos, the material universe can be permanently changed by their actions. For this reason, daemons constantly seek egress into the realm of mortals. When a Warp breach gives the daemon legions a chance to enter the mortal realm, all rivalries and vendettas are put aside. The numberless armies of the Immaterium burst forth, united by a shared goal -- the total conquest and subjugation of realspace. The daemon-hunting Ordo Malleus of the Inquisition fears that with the exponential increase in the number of humans in the galaxy who now manifest psychic abilities, the material dimension will soon be overwhelmed by these daemonic incursions. Once the Ruinous Powers have glutted themselves on the souls of all the mortals in the galaxy, their armies will fall upon each other like hyenas over a fresh corpse, but by then it will be too late. All that could exist in such a nightmare are the daemons themselves and those few mortals who survive by the sufferance of their masters.

Being an intelligent entity of the Warp, a daemon cannot exist for long periods of time in realspace, any more than a mortal can survive unprotected in Warpspace. There are a few ways a daemon can breach the walls separating the Warp from realspace and gain entry into the material universe.

Possession

Daemons can possess mortals on the other side of the barrier between dimensions by transferring some of their psychic power into the mind of a psychically "gifted" mortal victim. The mind of a psyker is the most susceptible to this influence, which is why the Imperium so greatly fears and controls psychic individuals. The daemons appear in dreams and visions, infusing their mortal host with a portion of daemonic power. This eventually leads to the destruction of the possessed mortal, who is known as a Daemonhost, as their physical frame is warped by the daemon to suit its own inhuman aesthetic. A few mortals willingly allow themselves to be possessed, glorying in the superhuman abilities they gain, even though the energies they crave will soon destroy them. Though the physical and psychic power of a daemon is severely limited by the physical body it possesses, the scope for mayhem and carnage is still great. Possessed mortals, particularly those who already have power and influence, can start rebellions and wage wars, plunging whole worlds into centuries of bloodshed and anarchy. The history of the galaxy is littered with devastating conflicts caused by Imperial military commanders, belligerent army generals and political leaders who have been touched by a daemon's fell influence.

Some Heretics who serve Chaos Cults or the Ruinous Powers directly willingly offer themselves as Daemonhosts through daemonic pacts such as those pursued by the foul Possessed Chaos Space Marines. Another way to allow a daemon to manifest itself in the Materium is by preparing a suitable mechanical vessel for it to inhabit. Weapons and vehicles from Dreadnoughts to Cruisers can be ritually anointed through painstaking rituals and large sacrifices of mortal lives to serve as a host "body" for a daemon. This process is far from easy, as daemons dislike mechanical bodies for they are far more difficult to bend to their will and reshape than a biological one.

Daemonic Incursions

Daemons strongholds — Daemonic strongholds in the Eye of Terror

In order for a daemon to break through into the mortal universe, there must be a breach of the barriers between Warpspace and the material realm -- a Warp rift. These are breaches in the fabric of reality that can vary in nature and size, such as the massive Eye of Terror or the Maelstrom. Sometimes these occur randomly; at other times, either mortals or the Chaos Gods themselves bring about their creation by some supernatural act. The size of the breach can vary tremendously, from a slight thinning of the dimensional walls to immense wounds in reality that allow the daemonic legions to invade en masse.

At times when certain conditions like the appearance of a Warp Storm or a sorcerous ritual have weakened the barrier between the Warp and realspace, a daemon can possess a mortal and turn him or her into a living portal through which whole daemonic hosts can pass for a time into the material universe. These daemonic incursions can taint realspace severely, often twisting and reshaping whole planets until they are lost into the Warp, becoming a part of the Immaterium and thus transformed into Daemon Worlds. It is not surprising that the Inquisition's Daemonhunters, the Ordo Malleus, are granted unlimited resources and political power by the High Lords of Terra to deal with such terrible threats to the continued existence of Mankind.

Often, it is the tumultuous movements of the Warp itself that create a break into the material realm, allowing daemons to spill through the resulting breach. This might happen by chance; events such as the onset of Warp Storms, Warp-Drive implosions or a rogue psyker's mind suddenly exploding with raw power can cause a rift to appear into the Immaterium. At other times, the deliberate rituals and blood sacrifices of Chaos-worshipping mortals can allow the teeming hordes of the Chaos Gods to smash through into the material realm. Sometimes, simple mortal suffering, death and misery on a massive enough scale can form a Warp rift that a daemonic legion might use as a portal. Some Warp rifts last mere hours, or even moments, for the nature of Chaos is ever impermanent. A daemonic army that has passed through such a rift can become trapped in realspace and will swiftly succumb to the constant leeching of the Chaos energy required to maintain its presence.

Of these, the greatest and most dangerous Warp rift is the Eye of Terror, which has lasted for more than ten thousand standard years. The Eye can be seen as a purple-red bruise upon the firmament from fully half the worlds claimed by the Imperium. It was created by the birth of the Chaos God Slaanesh in the early 30th Millennium and is home to unnumbered Daemon Worlds fought over by daemons and mortals alike, the infamous Traitor Legions of the Chaos Space Marines amongst them. Another Warp rift of excessive magnitude is the Maelstrom, found near the galactic core and a haven for thousands of pirates and Renegade Space Marine Chapters. Other, less widely known Warp rifts exist, such as the Heart of Darkness near to the world of Atilla, the Storm of Judgement that engulfs almost all of the Caradryad Sector, Hell's Gullet, which threatens to swallow the Berillian System whole, and the infamous Screaming Vortex that marks the border between the Calixis Sector and the frontier of the Koronus Expanse in the Halo Stars.

Random Warp rifts are often caused by Warp Storms -- roiling expanses of turbulence within the Realm of Chaos that are echoed in realspace, restricting Warp-dependent travel and communication. If they become focussed or powerful enough, they can pull the fabric of reality taut or even tear it open. Compeletely unpredictable, Warp Storms can be isolated to single planets or expand to encompass whole sectors. One of the worst Warp Storms ever recorded in human history cut Terra itself off from the rest of the galaxy for the entire 5,000-year-long epoch known as the Age of Strife. The unfortunate worlds in the vicinity of such a cataclysmic event can become the playgrounds of daemons until the storm finally expends itself. A few Warp Storms have endured for so long that they can be considered permanent, their self-sustaining energies trapping nearby planets and star systems in a quagmire of roiling Chaos.

Without the Warp, there would be no psykers, no interstellar travel and no interplanetary communication. In fact, the Warp is essential to the survival of humanity. Spacecraft travel through its shifting tides, capable of travelling thousands of light years in a fraction of the time a journey using conventional reaction drives at sub-light speeds would take. By such means, humanity is bound in a single interstellar Imperium, led by the divine Emperor of Mankind.

Through astrotelepathy and the guidance of the psychic mutants known as Navigators, the worlds of the Imperium are able to maintain their fragile bonds. The Emperor's will may be mighty, but His reach is long only because His fleets can travel through Warpspace, the fragile bubbles of reality that protect each warship held up by complex Geller Fields and raw faith.

While Mankind would have a fraction of its current numbers and strength without the Warp, Chaos in its turn would be much diminished without the presence of humanity in the galaxy. The Chaos Gods drink emotions and thoughts, growing bloated with psychic power in the process. Over the millennia, each has fed on an aspect of human nature: rage, desire, corruption and inconstancy. Strengthened and moulded by the collective thoughts and emotions of the inhabitants of reality, the Dark Gods nurture in Mankind those same passions that sustain their very existence. As humanity has spread across the stars, its numbers have grown immeasurably, fuelling the Chaos Gods. So the circle is established, with mortal follies and weaknesses feeding the Dark Gods and those same gods then encouraging Mankind in turn to further follies and weakness.

SpaceMarineinHell — A lone Space Marine confronts a hellish daemonic incursion into realspace

Humanity has long been able to use the power of the Warp -- magicians, seers, witches, mediums, shamans and exorcists have all trapped into its power across the breadth of human history, albeit often unwittingly. Psykers such as these manifest their powers by drawing upon the Warp, siphoning its unnatural energy to hurl blasts of energy, teleport objects, send their thoughts across space and time and perform countless other "miracles." Once, the gift of true psychic power was confined to only a few helpless individuals who usually fell victim to superstitious prejudice in Mankind's distant past. However, the number of psykers is rising in the galactic population of humanity with every passing century. This constitutes a profound evolutionary change for Mankind. Every time a psyker draws upon the Warp, he disturbs its natural flow, creating an eddy that may simply die away or be fed by other movements until it becomes a raging tempest that feeds a Chaos God. Each psyker causes a pinprick of disturbance within the Warp; each can be the seed of a Warp Storm; each can rouse a Chaos Power to unthinkable conquest.

The invasion of a daemonic army is analogous to hell being unleashed upon reality. Free from the physical limitations of a mortal force, a daemonic legion can appear and disappear at will. On occasion, it will mass for a great attack; at other times, individual packs of daemons will hunt across the affected globe, terrorising the populace, randomly enslaving and killing. Those mortals with even the least psychic potential suffer first as the influx of Warp energy releases the latent power of their mind, immolating them with magical fire, turning them into rocky statues, or causing their brains to simply explode. Poltergeist activity and random bursts of pyrokinesis can ruin buildings in an instant. People hear deranged screams and lurid whispering whilst unnatural stenches taint the air.

A daemonic invasion is all but impossible to stop by conventional means, for the very act of warring against daemons feeds the psychic power keeping them in realspace with fear and hatred. Only the closing of the Warp rift can deprive the daemons of their power. Often, there is nothing that can be done but battle against the incursion until the Warp rift runs its course. Battles fought against a daemonic incursion are utterly different than those against mortal foes, for defensive structures and garrisons have little to no effect. To wage war against invading daemonic hosts, an army must be ready to respond to the most sudden appearances of its adversaries.

To compound matters, the motivations behind daemonic incursions are unfathomable. Even the Tyranids, who are so alien as to be beyond the ken of man, war for sustenance and survival. Instead of these base drives, the objectives of a daemon commander will often be completely obscure -- they might be to slay a million mortals, to retrieve a single artefact, or to kill the grandchildren of those that once banished them back to the Warp. Other times, the Daemons have no goal or plan at all, and the gibbering creatures of the Immaterium make decisions according to opportunity and their intrinsic nature.

To fight a daemon army is to fight a twisting tornado of unreason and despair. Even then, the Imperium cannot allow the knowledge that such foes actually exist to spread. The human survivors of such conflicts are invariably confronted by the Inquisition and mind-wiped, quarantined in forced labour camps or even -- in extreme cases -- become the subjects of a worldwide Exterminatus event. Over the aeons, the galaxy has witness Warp-based catastrophes and daemonic incursions beyond counting. Since the inception of the Imperial Inquisition in the early days of the Horus Heresy, even the fact that such a thing is possible is deemed too dangerous for the citizens of the Imperium to know, for such knowledge breeds heresy as surely as a flyblown corpse breeds maggots. Because of this, the vast majority of knowledge concerning daemonic incursion has been eradicated from extant Imperial public records. What is known is recorded only in proscribed Imperial texts and heretical xenos scripts that the Inquisition has yet to destroy.

Types of Daemon

Greater Daemons

200px-Keeper of secrets — Keeper of Secrets, a Greater Daemon of Slaanesh

At the top of the daemonic hierarchy are the Greater Daemons whose immense power can be variable, depending on the whims of their patron Chaos God. Some, like Nurgle 's Great Unclean Ones, are only slightly less powerful than that of their patron God and in some cases they serve as temporary avatars of that God. Others, though immensely powerful by mortal standards, are allowed to embody only a fragment of the true collective power of their patron. Greater Daemons act as the wardens of their patron's realm in the Immaterium and have authority over the Lesser Daemons of their respective God. It is often they who lead daemonic incursions into the material universe. Such is their might that they cannot simply be summoned by mortal Chaos Cultists performing a sorcerous ritual like Lesser Daemons. A Greater Daemon needs to possess a mortal's living body in order to fully manifest itself in realspace unless a Warp rift or Warp Storm has come into being, essentially eliminating the barrier between the Immaterium and the mortal world.

Great Unclean One, Greater Daemon of Nurgle
Keeper of Secrets, Greater Daemon of Slaanesh
Lord of Change, Greater Daemon of Tzeentch
Bloodthirster, Greater Daemon of Khorne

Daemon Princes

The most powerful mortal devotees of Chaos try to gain the attention of their Dark Gods in order to gain the terrible power and great rewards that the Ruinous Powers can bestow upon their most favoured servants. Those striving in the pursuit of their God's designs are known as Champions of Chaos, whose ultimate, driving goal is to transcend mortality itself by becoming a Daemon Prince. Those mortals who become Daemon Princes are counted among the most powerful of the servants of Chaos, second only to the Chaos Gods and their Greater Daemons themselves. However, this path can as easily lead to another extreme. Throughout the path to power the Champion undergoes constant change, until either his patron Chaos God judges him worthy of daemonic ascension or his form finally is overcome by the accumulated mutations given through loyalty to Chaos and he devolves into a mindless Chaos Spawn. The goal for most mortal Chaos Champions is to be elevated to the rank of a Daemon Prince in the service of one of the Ruinous Powers or of Chaos Undivided. This was the reward granted to the surviving Primarchs of the Traitor Space Marine Legions who fell to Chaos during the Horus Heresy.

Lesser Daemons

Lesser Daemons are the foot soldiers of Chaos, providing the core of the Daemonic Legions. They are usually anthropomorphic in appearance and possess a calculating, malevolent intellect. Among the Daemons of Chaos they are the ones most likely to answer the summoning calls of mortal heretics who engage in blasphemous sorcerous rituals to call forth these entities into realspace.

Bloodletters
Plaguebearers
Horrors
Nurglings
Daemonic Steeds
Flesh Hounds
Daemonette
Flamers of Tzeentch

Daemonic Creatures

These more primal Warp entities are the lowest type and least intelligent of the daemons. They are often granted as servants to other daemons and occasionally, one of the Chaos Gods' more powerful mortal followers or Champions. Daemonic creatures can be further divided in type between Daemonic Beasts and Daemonic Steeds.

Daemonic Beasts

Daemonic Beasts are driven by a feral intellect and commonly used as hunting beasts by the Forces of Chaos.

Beast of Khorne: Flesh Hound
Beast of Nurgle
Beast of Slaanesh: Fiend of Slaanesh
Beast of Tzeentch: Screamer

Daemonic Steeds

Daemonic Steeds are prized mounts used by the more experienced Champions of Chaos. Earning one of these creatures from the Ruinous Powers can be as dangerous as facing them in battle.

Steed of Khorne: Juggernaut
Steed of Slaanesh: Mount of Slaanesh
Steed of Tzeentch: Disc of Tzeentch
Steed of Nurgle: Rot Fly

Unaligned Daemons

Apart from the four major Ruinous Powers that form the Pantheon of Chaos Undivided, there are numerous minor daemonic entities in the Warp who are Chaotic in nature too. The Chaos Gods tend to have less direct control over them, though they still serve the overall universal force that is Chaos.

The Fury, Daemonic Beast of Chaos Undivided
The Soul Grinder, former daemon of Chaos Undivided, dedicated to the Forge of Souls, an organization of daemonic smiths in the Realm of Chaos which is independent of the control of any of the major Chaos Gods and uses the Soul Grinders to maintain that independence.

Daemonic Relationships with Mortals

Mortal worshippers of the Chaos Gods can interact with daemons in ways other than simply fighting alongside them.

Possessed Chaos Space Marines

Some Chaos Space Marines willingly allow daemons to inhabit their bodies so that they can enter the physical universe. Rather than the daemon completely taking control, as in the case of possession by a Greater Daemon, these Lesser Daemons form an amalgam of Chaos Space Marine and daemon commonly referred to as a Possessed Chaos Space Marine, or simply the Possessed. The Possessed are potent warriors, combining the abilities of a Chaos Space Marine with the sorcerous psychic powers of a daemon.

Closely related to the Possessed are Obliterators, which are mysterious, daemonically-warped Chaos Space Marines. They have become an amalgam of a Chaos Space Marine, a Lesser Daemon and heavy armor, and bear the ability to transform their bodies into powerful weapons, making them walking gun platforms. Obliterators have their own cult, which is most closely connected to the Iron Warriors Traitor Legion. It has since been learned by the Inquisition that the Obliterators were once the Techmarines of the Traitor Legions, horribly warped and transformed by their ten millennia of exposure to Chaos.

Daemon Weapons

Some daemons can be forced into servitude by being imprisoned within the physical structure of a personal weapon; these mighty artefacts of Chaos are called Daemon Weapons. Daemon Weapons are extremely rare, but also very powerful, often able to tear apart reality, shoot powerful sorcerous bolts of psychic energy, grant their wielder extraordinary physical attributes, or perform other such unnatural feats. A Chaos Warrior must exercise great caution with these weapons, however, as the imprisoned daemon will often try to rebel against its master and attempt to devour the wielder's soul.

Chaos Spawn and Daemon Princes

As a mortal worshipper of Chaos grows more powerful with each of his victories in the name of the Ruinous Powers, his patron God or Gods will sometimes reward him with mutational "gifts"; by the same token, with each failure, the God could also curse him with the same changes. However, the Chaos Gods are notoriously fickle and often bestow their gifts of change without rhyme or reason. These gifts can include mutations such as extra arms, tougher skin, wings or the ability to shoot fire from one's hands, equipment such as exotic weapons or powerful armour, or even daemonic followers such as the Daemonic Mounts. With each gift, the warrior becomes partly daemonic himself, being tied more and more to the will of his God and becoming more and more a slave to that entity's will. As a servant of Chaos continues to distinguish himself, and successfully carry out his God's desires, this individual will continue to receive Chaotic gifts. These gifts can grant the receiver untold arcane powers that will make him potentially as powerful as a Greater Daemon. As the Chaos warrior attains more and more gifts, he will ultimately face only one of two possible fates for a mortal in the service of the Ruinous Powers:

If the warrior receives too many gifts and is unable to endure any more, he can be transformed into a Chaos Spawn. Some particularly powerful Chaos Sorcerers have the ability to grant this dubious "gift" to a foe, instantly mutating himinto a Chaos Spawn. Any servant of Chaos who has spent too much time in contact with the warping power of Chaos or the Immaterium -- perhaps through dwelling in the Eye of Terror -- may become a Chaos Spawn, even without the intervention of the Chaos Gods. Chaos Spawn are wildly mutated beasts of varied physical form, no two exactly alike, and are generally insane or non-sentient. A Chaos Spawn lives out the remainder of its pitiable existence at the whim of its God, serving as both gibbering cannon fodder for the armies of the Ruinous Powers and as a warning of the consequences of failure to all the servants of Chaos.
A particularly successful Champion of Chaos who is able to withstand the "gifts" of his God and successfully champion the goals of the Ruinous Powers on multiple occasions can eventually become an exalted Daemon Prince. A Daemon Prince is among the most powerful beings that can be found on the battlefields of the Warhammer 40,000 universe. They are frequently massive in size -- much larger than a man and at least 10 feet in height -- and are very skilled warriors with the experience of hundreds of campaigns behind them. Like all daemons, Daemon Princes possess many potent psychic abilities. There are two types of Daemon Prince: those who have fully and willingly abandoned their mortal, physical form and have become a daemon in their own right and those who have not yet lost their mortal form. The first type can display many of the powers of a Greater Daemon, but specialised anti-daemonic weapons and psychic powers can be used to banish them to the Warp; the latter, while powerful and infused with the psychic powers of the Immaterium, are immune to such weapons, but can still be slain by purely physical means.

Daemonhost

Some especially Radical Inquisitors of the Ordo Malleus believe that one of the best ways to defeat the Chaos Gods is to turn their own followers against them. To this end, they will force a daemon into possessing a human body and, using powerful psychic spells, rituals and charms, bind it to the Inquisitor's will. These enslaved daemons are called Daemonhosts, and they are sometimes brought to the battlefield where they use powerful daemonic abilities to destroy the Inquisitor's foes. However, such Inquisitors are seen as dangerous heretics by their more conservative Puritan brethren, and sometimes find themselves being hunted as though they were traitorous heretics themselves; by the same token, other Imperial forces will usually hesitate at the prospect of fighting alongside a daemon, as this is heretical in the extreme. The Grey Knights in particular despise the thought of these so-called daemonhosts, and refuse to fight next to such abominations to the will of the Emperor under any circumstances. Chaos Cultists and Chaos Sorcerors will perform the exact same ritual, albeit for a different purpose, in order to have daemons that are able to maintain a physical form, but still possess many of the strengths of a daemon. Certain Chaos Space Marine leaders, notably Abaddon the Despoiler, will bind his daemons in such a way that they possess little free will.

Daemon Engines and Daemonically-Possessed Vehicles

Daemon Engines are similar in nature to Daemon Weapons; they are special tank-like machines which are forged in the realm of the Dark Gods and controlled by an imprisoned daemon. They frequently carry powerful cannons which make them useful in sieges. The most common type of Daemon Engine is the Defiler created by the Traitor Legions since the end of the Horus Heresy, a large spider-like combat walker mounting the battlecannon typical of Imperial Guard main battle tanks like the Leman Russ. In contrast to Daemon Engines, daemonically-possessed vehicles are normal tanks and other Imperial armoured vehicles that have had a daemon sealed within them through the use of Chaotic sorcery, allowing it to control the vehicle in place of the normal Machine Spirit. This can be a strong advantage for the Forces of Chaos because the daemon, unlike a normal crew, cannot be killed or stunned by enemy attacks. The difference between a daemonically-possessed vehicle and a Daemon Engine is in the crafting - a possessed vehicle was built prior to its possession for a different purpose; a Daemon Engine has the daemon imprisoned within its structure as a part of the vehicle's original creation. Possession also comes in two forms: a normal daemon possession like that of a Possessed Chaos Space Marine, and a possession that is more akin to a parasite. Where the former daemon receives direct control of the vehicle, the latter will actually become the vehicle. With a parasitic possession the vehicle becomes a living being like the daemon, able to regenerate lost armaments or treads just as a living creature heals its wounds.

Sources

Realm of Chaos: Slaves to Darkness
Realm of Chaos: Lost and the Damned
Codex: Chaos Space Marines (3rd Edition, 1st Codex)
Codex: Chaos Space Marines (3rd Edition, Revised Codex)
Codex: Daemonhunters (3rd Edition)
White Dwarf 274 (UK), "Index Malleus"
Liber Chaotica
Warhammer 40,000 Rulebook (4th Edition)
Codex: Chaos Space Marines (4th Edition)
Codex: Chaos Daemons (4th Edition), pp. 4-13
Codex: Chaos Daemons (6th Edition), pp. 6-20, 24
Warhammer 40,000 Rulebook (5th Edition)