From the Darkness

From the Darkness was an infamous purgation campaign carried out by the Mortarchs Serpentia Space Marine Chapter against the recalcitrant cardinal world of Karra II.

History
In the wake of the Reign of Blood and the Plague of Unbelief, Chaos Cult sects rose up across the Imperium. On the cardinal world of Karra II, Ecclesiarchy Cardinal, Potur Kray the illuminator, descends into the depravity of pleasure, and succumbs to the will of Slaanesh. For over eighty years he poisoned the minds of his subjects and population, culminating in all-out rebellion and hedonism as the world erupts in an orgy of ecstasy and violence. However, amid the chaos, the shadows begin to deepen, and grey, smoke like fog begins to form amidst the fires and incense. This fog grew, and deepened, until cities were blanketed in a thick layer of impenetrable smoke. The screams rose -- not the screams of pain and pleasure, but screams of fear -- mixed with a hollow, bone-chilling rattle. Within weeks, the screams came to an end, and nothing but silence haunted the deserted cardinal cities.

The smoke receded, revealing the once sanctified constructs now hideously disfigured with chaotic depravity, and littered, from the highest tower to the lowest sewer, with the bodies of slaughtered heretics. Imperial forces that respond to the supposed threat arrives to find not a soul alive on the surface of the world, and the cardinal's sins exposed to the light. Of the attackers, no sign was found, save for a single, solitary mark, carved into the wall above the butchered, mutated body of the heretic cardinal. A frightening symbol in the shape of a coiled, skeletal serpent.