Chaos Space Marines are one of the most feared and reviled factions in the Warhammer 40,000 universe. Once loyal warriors of the Imperium of Man, they betrayed the Emperor during the Horus Heresy, a galaxy-spanning civil war that nearly destroyed humanity’s dominion. These traitor marines are now servants of the Chaos Gods—Khorne, Tzeentch, Nurgle, and Slaanesh—each embodying different aspects of chaos such as bloodshed, sorcery, decay, and excess. As a result, Chaos Space Marines have undergone horrific physical and mental transformations, becoming twisted parodies of their former selves.
Chaos Space Marines hail from the nine Traitor Legions that turned against the Emperor, as well as various renegade chapters that have since fallen to chaos. These warriors are equipped with ancient and powerful wargear, often corrupted by the dark energies of the warp. Their power armor, once a symbol of their loyalty to the Imperium, is now a twisted and baroque reflection of their allegiance to the dark gods, adorned with chaotic sigils and grotesque mutations. Their weapons range from corrupted boltguns to daemon-infused blades, capable of tearing through the most resilient of foes.
On the battlefield, Chaos Space Marines are unmatched in their ferocity and brutality. They are masters of both conventional and unorthodox warfare, often employing terror tactics, psychological warfare, and dark sorcery to achieve their goals. Their ranks include various specialized units, such as the Khorne Berzerkers, who revel in close combat slaughter; the Rubric Marines of Tzeentch, imbued with potent sorcery; the Plague Marines of Nurgle, who spread disease and decay; and the Noise Marines of Slaanesh, who use sonic weaponry to devastating effect. Driven by a thirst for power, revenge, and the favor of their dark patrons, Chaos Space Marines are a relentless and ever-present threat to the galaxy, embodying the eternal struggle between order and chaos.