Through the cold empty space between the stars moves a shadow of utter darkness, a vast, impossible conglomeration of voidships, a space hulk of the deep. Trapped within warpspace it has grown, drawing to itself new ships and meteors. Ever growing, ever hungry. The Primogenitor is the end of dreams, the iconoclast, the destroyer of man. Vomited forth from the Crimson Path the Primogenitor heralds the destruction of the Imperium.
Deep inside the mighty space hulk a cancer fester. Disease, corrosion and atrophy grows and contaminate, spreading out from the dark heart of the Pertinacious, capital ship of the Death Guard warband known simply as the Rot. The Unbroken of the Rot are renegades from their legion, cast out to drift upon the waves according to the will of Nurgle. Once they stood with their father when he cast of the Imperial chains, but over time a new heresy grew within them, abandoning the belief of their brethren they sought the true elsewhere. Taking to the stars they traveled the Great Eye for millennia, until the finally the Pertinacious descended into the Primogenitor embrace, a burial and a revelation.
The Unbroken seldom leave their burrows, preferring to sink ever further down into meditation. Inside these swamps and marshes they sit, staring into the abyss, opening up their minds to the one single truth they seek. But when they growth of the tumor gardens and plague pits are threatened they stir, slowly rising again to wage war as they did at the dawn of the Imperium.
The Iron Troika is sworn to protect apostle Vorg from all threats, even from fellow legionnaires. They seek out the most ferocious parts of the battlefield, bringing death to all unbelievers. Vorg’s iron cave is centered deep inside what remains of the Pertinacious, a wet hole with sentient slime covering the walls. Inside this sacred place he guides his fellow Unbroken as they follow their own roads to enlightenment.
Few of the Unbroken go into battle armed with bolters, their resources are dwindling and they save their guns for the truly worthy foes. Looking down upon their weak opponents in pity and contempt they cut and crush and break them beneath an iron wall.
The noxious tribes inside the Primogenitor tend to scamper around the lairs of the Rot, desperate for protection from the predators in the night. Most of the Unbroken pay little heed to these mortals, but a few kind warriors will take pity and accept their subjugation, enslaving a tribe they deem worthy. The Unbroken will then herd the thralls on to the killing fields, ever searching for humans strong enough to accept the tainted seed of Mortarion.
The kinder Unbroken will sometimes stir from their somnolence and lead mortal maggots into slaughter. For like all gods they take comfort in the violent acts of men. The degenerate humans worship they masters, often referring to them as the Kindly Ones.
Transubstantiation is never easy nor without pain. It is the destruction of the ego and the unfettering of the id, a birth in fire and blood. But to undergo the metamorphosis and emerge from the Sea of Souls is a reward men are willing to sacrifice anything to achieve. The path of Pestilence is slow, but those blessed by Onogal’ Rot will eventually shed their physical self and emerge triumphant as a plaguebearer. Remnants of their former existence cling to the Unborn like hooks, anchoring them and allowing them access to real space.