Since Daemon Princes have been transformed into semi-autonomous extensions of the Chaos God they serve or of Chaos Undivided, they are now entities of the Warp and can never truly be killed in the material universe, only banished into the Immaterium for a specific amount of time, usually 1,000 standard years. They are embellished with horrific decorations, fluttering Chaos banners, Daemonic gargoyles, beast-headed weapon muzzles and other icons of Chaos, making them as much a utilitarian statement of the Chaos Space Marines' hatred of the Imperium of Man and its Emperor as a war machine. In realspace, Greater Daemons manifest as huge, terrifying creatures capable of slaying scores of warriors and destroying even main battle tanks. They have strange, sorcerous powers drawn from the psychic energy of the Warp and are virtually impervious to mortal weapons. The Plague Marines have dedicated their loathsome existences to spreading corruption and decay across the universe. The Plague Fleets of Nurgle that periodically spew forth from the Eye of Terror are captained by the Plague Marines, who intend to spread Father Nurgle's Warp-spawned contagions and pestilences across the myriad star systems of the galaxy.

His skin itches beneath his ceramite shell. His body throbs with pain. His mind aches under the scrutiny of a thousand roiling Warp-forms, each competing to conquer his flesh-form and alter it. As the ritual of reshaping concludes, the marks of the Daemon begin to manifest -- tendrils, curved horns or wings, all dripping with gore. The Possessed rises, forever changed by the powers of the Warp. It has been conjectured that the Furies are made of the souls of mortals that could never decide which of the Gods of Chaos to serve -- not because of a genuine love for all four of them in the guise of Chaos Undivided, but from a continuous swaying of worship of one Chaos God to another, driven only by the prospect of personal gain. The forces of Chaos, also spelled Forces of Chaos, sometimes referred to by the defenders of the Imperium as the " Archenemy" and as " Renegades" or " Traitors" when they formerly served the Imperium but were corrupted, is a catch-all term that includes all of the myriad mortal and Daemonic servants of the individual Ruinous Powers of Chaos and of the universal power of Chaos Undivided. This collection of beliefs upheld the core values of reason, science and secular progress over older traditions of religion, superstition and faith that had long defined many of the human worlds that had fallen into darkness during the Age of Strife after the fall of humanity's first interstellar civilisation. The Emperor Himself declared that Mankind would never be free to progress and advance to its destined position as the pre-eminent intelligent species in the Milky Way Galaxy until churches, idol worship and superstition were swept aside. Soul Grinders are the ultimate Daemon Engines, the fusion of powerful Daemonic entities with machines of war that originate from outside of the Immaterium but have already felt the touch of Chaos.Others still are driven by insanity and profane visions, launching quests to upend the very fabric of existence and transform the galaxy into a twisted hellscape. Such a possession is a lengthy and agonising experience, as the Daemons within them infest their physical forms and reshape them to better suit their particular needs. Those who offer themselves up for possession usually spend solar months in rituals of debasement and scarification, offering up blood sacrifices and preparing their bodies to harbour a daemonic entity. They are used as insane behemoths to trample the enemy and are regarded with caution, as the madman within the Dreadnought can turn his wrath upon his comrades if there are no enemy units within range.

Many Astra Militarum troops have turned to Chaos over the centuries, including entire regiments of the Astra Militarum's Imperial Army predecessors that followed the Warmaster Horus into battle against the Imperium during the Horus Heresy. These Traitors represent the primary mortal troops available to the forces of Chaos, now known as the "Traitoris Militarum" in High Gothic to the defenders of the Imperium. Even ten millennia later, Chaos Lords are known to attract these followers of Chaos into their warbands and personal armies, which vary greatly in both size and strength. All planets and civilisations belonging to the Imperium can harbour Chaos-aligned organisations, which themselves are as diverse in practice and membership as is imaginable. From the blood-soaked sacrificial cults of Feral Worlds to the philosophical secret societies of more advanced planets, the temptations of Chaos can capture all. Plague Marines are those Heretic Astartes who have wholly dedicated their lives and souls to the service of the Chaos God Nurgle. Within their corpulent and disgusting power armour their bodies are bloated with disease, swollen with corruption and rank with decay even as they no longer are capable of feeling pain, the greatest mutational "gift" given to them by the Plague Lord. With its Lascannons blazing and enemy shots sparking harmlessly off its powerful hull, a Land Raider is a bastion of strength that can spearhead an offensive or form a mobile rallying point when used on the defensive.

This is because, unlike a possessed mortal body, these steel and ceramite shells can sustain a Daemon in the mortal universe for solar decades, even centuries. During this time, the shape of each Soul Grinder will change, as their metal body slowly becomes more similar to the true form of the Daemon possessing it.

They are not particularly large, but possess great destructive capabilities; a moderately large group of Horrors can easily dispatch a Chimera transport, or even a Leman Russ medium tank. Defilers are Daemonically-possessed killing machines: a massive conglomeration of metal with two giant gnashing claws, six barbed mechanical legs, and an arsenal consisting of a powerful built-in Autocannon along with several other smaller weapons, though the weapons mix can differ dramatically from one Defiler to another.Once these new Rhinos are in their hands, Chaos Space Marines deface all Imperial insignia, attach banners proclaiming their allegiance to the Chaos Gods and festoon the vehicles with spikes, blades and grisly trophies that transform it from the service of the Corpse Emperor to that of his greatest enemies. These vast creatures tower over other regular infantry troops. In fact, they are as wide as Terminators are tall, giving them an impressive air of solidity and menace that is only enhanced by the gargantuan claws that they're armed with. This insanity is also possibly caused by the Machine Spirits of his weapons and armour fusing into a destructive Daemonic entity after infection by the virus. Obliterators are never part of an existing Traitor Legion or Renegade Chapter of Chaos Space Marines; they prefer to sell their services to the highest bidder amongst the forces of Chaos in return for access to the Archeotech that they crave.