Perspectives: Death Guard
It was that bastard whoreson Typhon's fault.
Sevastor knew it. They had heard it. How the First Captain had come back to the fold only to discover a conspiracy among the Navigators. He executed them and pretended his powers, the legacy of his shameful birth, could lead the Legion to Terra. Had this been a mistake? Had this been a lie? They did not know but he had led them here, in this place where the Warp seeped through their vessels bearing hateful change and decay to their forms. The Praetor gritted his teeth and tried not to howl in frustration. Astartes had been made to resist any mortal disease but the pathogens of the Sea of Soul had slipped through their armors, through their protection. They had been infected and the poison flowered through their veins. Their bodies screamed as the ships decayed, twin paradoxes he could not help but admire. Metal rusted and bodies sickened but they bore new life. Corroded plasteel was covered in vines spreading like veins, flowers corpse pale providing pale luminescence. And in the Death Guard? Sevastor was no Apothecary but he did not need their diagnostics to feel his healing system came into overdrive, sealing wounds with tumorous growths, extending as the world extended, confined as the world confined.
This was not the Endurance, this was not any vessel anymore. The straight hallways had become twisted paths, the walls hedges of rotting briars extending to the infinite. His boots made the soft floor, now moist black earth rich with maggots, squelch with wet sounds. Now there were no places left, no recognizable landmarks, only sometimes an obscene reminder of what they had been emerging from the undergrowth. Once Sevastor had been surrounded by his squad but even as the path tightened, he had lost sight of them. It had been another pain, after the swelling belly, the burning fever, the gnawing hunger and the overwhelming thirst. Nerves scrapped raw as they fused with the armor, eyes filling with noisome fluids, shrinking in their orbits, bones growing in place where they never were meant to be. And the mind was not left alone. Even discounting the surroundings as a hallucination, memories intruded on the Astartes' every moment. The flowers had the face of those he had slain, human or xenos, sometimes brothers on the fields of Istvaan. And still he walked uncaring of the shades who surrounded him as the mists of Barbarus and tried to elicit remorse.
He walked without knowing why, without knowing where to. This was the way of the Death Guard. To endure, to walk through the most horrid battlefields the galaxy had to offer, to be subjected to the harshest circumstances. This had been their task, it had been their badge of pride. He knew that every living soul on the ship, from the lowest menial slave chained to their post to the Pale King himself walked as he walked, each step harder than the last, each move trying to move a mountain, walking along this never ending spiral he had long abandoned any hope to count. Small creatures laughed at his feet, not in mockery but in encouragement. He felt a gaze upon him, a great being vaster than the myriad stars watching him with something Mortarion had so rarely displayed: A father's love for his sons, an accounting of what was endured. It drove him forwards even as the world became pain, even as his entrails spilled from distended guts, even as the children of flies escaped his orifices as though his blood was made of insects.
How long did he walk? Days, weeks, years? In this place where time had no meaning, these words were useless. Later he would hear from the Neverborn he had completed forty-two circles of the spiral while his Primarch had completed all forty-nine and had knelt before the Grandfather itself, offering fealty to the Lord of All Things. There was a moment where nothing was possible. He fell and could not rise, face forwards in the moist earth, maggots climbing into him. And then he felt it. The power that watched him, who watched all sons of Mortarion offered him the choice it had offered to all. He could die truly. He could rest. He could make it all end. Others had chosen that fate and their bodies were mulch for the garden still their souls were free. Yet he felt the fierce love of the entity, of Grandfather Nurgle, surrounding him like a warm fire. Sevastor could endure. Sevastor could still move. His flesh was weak but his spirit still burnt with the desire of life. He still tried to crawl forwards on the path.
It was good, it proved that Sevastor was a hero, like in the legends of old. So many others had given up sooner, had not endured the dread alchemy of the Warp-born disease. The Praetor had completed the transmutation. Nurgle loved all its children but there are some who are most dear to its fecund hearth, those in which the drive to survive is strongest. Sevastor could move beyond fear, beyond doubt, beyond remorse and beyond mortal frailty. All he had to do was to take the mark, to surrender his soul to the care of the Grandfather.
"If agony doesn't keep you from wanting to persist. If the flame of life still burns bright in your form. If you know that a living dog is better than a dead hero, then kneel and do as your father does, as your brothers do. Accept our hands and we will always be with you, supporting you and helping you. Long have you been alone my son but now you shall never be without a friend, without a father."
So it spoke in the voices of the flies as they buzzed, in the whispering of open wounds and Sevastor felt like a hand of rotten wood and weeping stones being offered. He took it without hesitation. He wanted to live. He wanted to walk on Terra. There were still sights to be seen, enemies to be felt, slights to avenge. And as his fingers closed around the daemonic hand, he felt strength return to him, a boundless spring refreshing his burning limbs. The Garden slowly left the ships and Sevastor, and Pestilax saw that indeed he was not alone. His brothers were there mostly, even many of the human crew had survived and made the same oath. He would fight on Terra with his squads and avenge themselves on the False Emperor.
And they would be forever beyond pain, ready to rise again if their flesh should finally fail them. For this was the promise of the God of Life Unbound and unlike the tyrant of Terra, Nurgle always delivered.
Sorry it didn't leave me alone. I know it's a slight retcon but in my verse I try to make the Death Guard's fall to Nurgle more a consequences of their flaws rather than simply "Typhon is an asshole".
I risk to do this for the Nine Legions, or at least the cultists ones.