The Plague Ascendant: The Fall of Krastellan
The Plague Ascendant
Prologue: The Wages of Decay
In the grim darkness of the 41st millennium, Mortarion, Primarch of the Death Guard, waged his unending war against the Imperium with tireless resolve. Bearing the favor of Nurgle, the Plague God, he had become a harbinger of decay, wielding pestilence as a weapon against those who would defy the inevitability of entropy. His Death Guard, a legion of bloated warriors and corrupted war machines, had set their eyes upon Krastellan, a Forge World of the Adeptus Mechanicus in the Segmentum Obscurus. For months, the planet had suffered from outbreaks of a virulent disease that afflicted not only organic life but even the machine spirits themselves.
Reports trickled in from the explorator fleets of a shadow moving through the void like a ghost—Mortarion had come, and with him, the stench of doom.
The Rusting Sprawl
The Corroded Outskirts of Krastellan
The opening clash erupted at the borders of Krastellan’s manufactorum districts, a sprawling expanse of rusting machinery and towering cogitator stacks. Here, the Adeptus Mechanicus had established a defensive perimeter around a plasma reactor whose energy fed the Forge World’s central production. The outer defenses consisted of Skitarii Vanguard armed with radium carbines and transuranic arquebuses, bolstered by Kataphron Breachers wielding graviton cannons and torsion crushers. Overhead, Serberys Raiders patrolled, their mounts’ augmentations gleaming coldly under the dim light.
The Death Guard came like a tide of corruption, their ranks bloated and festering. Plague Marines, led by Champion Gorvoth the Undying, marched with grim determination, while Blightlord Terminators lumbered behind, their armor eternally weeping with putrescent fluids. Above them loomed Mortarion, his immense form shrouded in a cloud of pestilence. The scythe Silence glowed with malevolent energy in his grip, while The Lantern at his side flickered with an unnatural light.
The Clash
The battle began with Mortarion calling upon his psychic power. He conjured Rotwind, a haze of fetid fog that rolled across the battlefield, thick with the stench of rotting flesh and chemical decay. The fog did more than obscure vision; it corroded the very armor of the Skitarii, rusting it away before their eyes. Bolts of radium fire passed through the mist, their efficacy blunted by the miasma’s touch. Those that did find their mark either deflected off Mortarion’s daemonic flesh or withered against his invulnerable save—a dark blessing from Nurgle that shrouded him in a veil of entropy.
As Mortarion advanced, the true horror of his abilities manifested. His wings, ragged and pockmarked with sores, unfurled and beat against the air, launching him into the midst of the Skitarii. As he landed, a pulse of noxious energy emanated from him, thickening the air with decay. Mortarion's form, both immense and repulsive, seemed to grow larger in the eyes of those around him, his monstrous aura a weapon as terrible as any scythe. With a swift swing of Silence, he cut down a score of Skitarii, the blade leaving trails of filth that ate away at the bodies of those it did not kill outright. The fallen quickly began to twitch, their flesh splitting open as Nurgle’s diseases took root in their corpses.
Gorvoth and his Plague Marines moved in close behind their Primarch. With bolters belching foul ammunition, they laid down suppressive fire, each plague bolt detonating into a burst of caustic slime that chewed through armor and flesh alike. Gorvoth himself swung his manreaper in wide arcs, each strike accompanied by a wet, sucking sound as his blade cleaved through cybernetic limbs and decomposed muscle. The Champion’s laughter bubbled up through the vox-grille of his helmet, a sound more like the gurgling of a clogged drain than any mirth.
The Horror of the Psyker and Daemon
As Mortarion continued to carve his way through the defenders, his psychic power swelled, the air thick with his daemonic influence. He invoked Putrescent Vitality, unleashing a burst of necrotic energy that washed over the battlefield. The greenish glow that emanated from his form warped and distorted reality, tainting the ground and air. Where the light touched, the Mechanicus’ machines began to fail; cogitators sputtered and died, and servo-arms seized up as their circuits corroded. Flesh fared even worse, with the Skitarii dropping to the ground, clutching at their throats as they coughed up black bile.
Mortarion raised The Lantern and fired. The weapon’s warp-corrupted beam ripped through the ranks of the Mechanicus, vaporizing a Kataphron Breacher in a flash of light. The machine’s remnants fell to the ground as little more than a slurry of slag and rancid oil. The beam continued its path of destruction, striking a cluster of Servitors. Their bodies swelled grotesquely before exploding in showers of offal and circuitry.
The Mechanicus fought back with grim determination. Kataphron Breachers unleashed graviton blasts that hammered into the Death Guard’s ranks, while the Skitarii fired radium rounds that detonated on impact, showering the Death Guard with lethal radiation. Even Mortarion was not impervious to the onslaught, and his armor sizzled as it absorbed the brunt of a plasma blast. Still, the Primarch fought on, the blessing of Nurgle fortifying his resilience beyond mortal comprehension.
The Despairing Maw
Then, as the battle raged on, a rift tore through the fabric of reality at the edge of the battlefield. Known as The Despairing Maw, this warp phenomenon manifested as a swirling vortex of darkness, from which daemon-beasts of Nurgle emerged. Beasts of Nurgle, massive and bloated, surged forth, their slobbering maws wide open as they loped towards the defenders. Plague Drones buzzed overhead, their grotesque riders casting pox grenades into the midst of the Mechanicus formations.
Yet, The Despairing Maw was not simply a portal; it was a hungry maw that consumed the souls of the dying, pulling the recently slain back into the warp. Even the daemons emerging from it were not spared, as some were dragged back into the swirling darkness, their forms unraveling into viscous streams as the maw fed upon their essence.
The Duel
Tech-Priest Dominus Vireon Thalax, the commander of the Mechanicus forces, stepped forward to meet the challenge of Mortarion. His cybernetic limbs glinted in the dim light as he raised his power axe, its blade charged with an electric hum. The clash of Mortarion’s daemonic form and Thalax’s mechanical bulk was a brutal display of raw power versus cold logic. Thalax swung his power axe, the blade glowing blue as it crackled with disruptor energy. Mortarion parried with Silence, their weapons clashing with a resounding crack that echoed across the battlefield.
Mortarion grinned behind his helm, his voice echoing like the rattle of chains. “You cannot hope to resist the inevitable, tech-priest. Your machine god’s blessings will rot, your circuits will fail. The embrace of Nurgle is inescapable.”
Mortarion channeled his psychic might into a surge of necrotic energy, blasting Thalax back. The Tech-Priest’s armor began to corrode, the intricate mechanisms within grinding to a halt as corruption spread through them. The machine spirits in Thalax’s limbs wailed in agony as they were consumed by decay, their binary prayers turning to static.
The Aftermath
With Thalax broken, the Adeptus Mechanicus lines began to waver, and the Death Guard pressed their advantage. The plasma reactor, once the heart of the defense, was soon overrun by the plague-ridden warriors, and the stench of death hung thick in the air. The survivors of the Mechanicus withdrew, dragging their damaged constructs away to fight another day. The battlefield was a ruin of rust and corruption, the once-pristine manufactorum reduced to a rotting wasteland.
The Price of Decay
After their victory in the first battle, Mortarion and his warriors consolidated their hold on the captured manufactorum district. The very ground seemed to heave and warp beneath the corrupting influence of Nurgle’s blessings. Pools of stagnant, toxic fluid seeped up through the cracks, and the once-gleaming manufactorums decayed into crumbling ruins. The stench of putrefaction was everywhere, and even the air seemed to crawl with contagion.
Mortarion brooded as he surveyed the battlefield. He could sense something deeper within Krastellan, a hidden power that lay dormant beneath the forges. As his warriors reinforced their positions and fortified the newly taken ground, the Primarch sent forth his Plaguebearers and Blightlord Terminators on a search for the secrets buried within the Forge World’s depths.
The Iron Tide
The Forge-Spires of Krastellan
The Death Guard’s conquest of Krastellan’s outer manufactorum district had not gone unnoticed. Deep within the Forge World’s network of towering spires and labyrinthine industrial sectors, the Tech-Priests gathered in councils of war. Led by Magos Prime Helrikkus Kaarn, an ancient and heavily augmented Tech-Priest, the Adeptus Mechanicus devised a strategy to halt the relentless advance of Mortarion’s forces. Kaarn, whose body was more machine than flesh, had overseen the defense of Krastellan for centuries and was determined to preserve the Forge World’s sacred technology from the corrupting touch of Nurgle.
The battle unfolded within the Forge-Spires themselves, a vast complex of towering structures that housed vital data-vaults and manufactorum facilities. The Forge-Spires were linked by a network of gantries, catwalks, and mag-lev platforms, while massive chimneys belched toxic smoke into the air, further obscuring the sunlight. Here, the Tech-Priests and their servitors had fortified their positions, with defensive emplacements of heavy phosphor blasters and arc rifles, and squads of Skitarii lined the platforms, ready to repel the invading forces.
The Adeptus Mechanicus had prepared an array of war assets for this conflict, deploying Triaros Armored Conveyors outfitted with neutron beam lasers to serve as mobile bunkers, while Ironstrider Ballistarii, their lascannons gleaming coldly, took up positions on the high ground. Helrikkus Kaarn himself commanded the forces from the central spire, directing his legions of cybernetic warriors and combat servitors with the cold precision of a data-savant.
The Death Guard’s Assault
Mortarion, undeterred by the formidable defense arrayed against him, ordered a multi-pronged assault. His forces included a greater variety of corrupted units than before, with Myphitic Blight-Haulers and Foetid Bloat-Drones providing mobile firepower to support the Plague Marines. The Daemon Prince Gloamfall, a twisted monstrosity birthed from the warp, accompanied Mortarion, his rotting wings spreading decay with every beat. Blightlord Terminators once again formed the vanguard of the assault, alongside squads of Plaguebearers that loped forward, their flesh glistening with rot and dripping with pus.
The Death Guard's weapons of war varied greatly, reflecting the many ways in which Nurgle's blessings could bring death. Some Plague Marines carried plague spewers, unleashing torrents of bile and acidic slime upon their foes, while others hefted blight launchers that lobbed canisters filled with virulent spores, spreading pestilence wherever they detonated. The Blight-Haulers unleashed their multimeltas and missile launchers, burning away metal and flesh alike with beams of searing heat and clouds of toxic gas.
The Clash
The Death Guard’s assault began with a volley of artillery fire. Plagueburst Crawlers, positioned at the periphery of the Forge-Spire district, unleashed salvos of plague-ridden shells. The projectiles exploded upon impact, releasing bursts of corrosive slime and viral agents that clung to the defenses. Skitarii Vanguard and their Radium Carbines retaliated, unleashing a deadly hail of fire that could pierce through even the hardened armor of the Plague Marines. Their weaponry, though effective, did little to slow the advance of the Death Guard, whose daemonic resilience allowed them to shrug off even the most grievous wounds.
Mortarion descended upon the battlefield with the wrath of a vengeful god. His wings unfurled wide, casting an oppressive shadow over the Mechanicus ranks as he landed amidst a cluster of Kataphron Breachers. With a sweep of Silence, he felled several of the augmented warriors in a single blow, the scythe's daemon-forged blade slicing through ceramite and cybernetic limb with ease. The ground beneath him erupted in boils and sores, as his mere presence corrupted the very land, creating pools of stagnant pus that bubbled and festered.
His psychic powers were unleashed with unparalleled fury. Mortarion invoked Gift of Contagion, causing the air to grow thick with pestilence. The Mechanicus warriors found their limbs weakening, their augmetics faltering as the plague gnawed at metal and flesh alike. Radium fire struck Mortarion’s armor, but it seemed to do little more than sizzle against the filth-encrusted plate, his Daemon resilience absorbing the blows.
The Daemon Prince Gloamfall joined the fray, his rotted form glistening with unholy ichor. His warpsword, a vile blade that oozed corruption, swept through the air in wide arcs, tearing apart Skitarii with contemptuous ease. The Daemon Prince bellowed a challenge to the machines that dared to defy Nurgle's will, his voice an unearthly gurgle. Gloamfall's warp-infused breath weapon spewed clouds of disease that withered metal and caused flesh to blister upon contact, adding to the cacophony of war.
The Iron Response
The Adeptus Mechanicus retaliated with machine-like precision. Helrikkus Kaarn activated a secretive war asset—a massive Castellan Knight, known as Ironclad Thallos, that strode forward from a recessed alcove within the central Forge-Spire. The Knight’s massive battle cannon roared, its shells exploding amidst the ranks of the Death Guard with devastating force. Streams of phosphor fire from the Knight’s shoulder-mounted incendiary cannons turned even the hardiest of Plague Marines to ash, and its iron gauntlet smashed the corrupted war machines beneath its tread.
The Triaros Armored Conveyors and Ironstrider Ballistarii unleashed their lascannons in tandem, focusing their fire on Mortarion himself. Though many shots were turned aside by his invulnerable save, several beams burned through the haze of his aura, searing the corrupted flesh beneath his armor. Mortarion staggered, briefly, before righting himself and leaping forward to engage the Castellan Knight directly.
The clash between Mortarion and Ironclad Thallos was nothing short of apocalyptic. Silence struck at the Knight’s armor, the daemon-scythe's warp-infused blade cutting deep gouges into the machine’s thick ceramite plating. In return, the Knight brought its massive chain-cleaver to bear, swinging the weapon with the force of a battering ram. Mortarion parried the strike, but the impact sent him reeling. The Knight’s cannons fired at point-blank range, bathing the Primarch in fire.
Yet, Mortarion's Gift of Nurgle was not to be so easily denied. He summoned forth Curse of the Leper, unleashing a wave of necrotic energy that washed over the Knight. The mechanical limbs began to seize and decay as corruption spread through its circuitry, and the machine spirit within writhed in agony as Mortarion’s power seeped into its cogitators. The Knight faltered, its limbs moving sluggishly as the taint of Nurgle infected its systems.
Turning the Tide
Just as the Death Guard seemed to gain the upper hand, the Mechanicus revealed another secret weapon: a Thanatar Siege-Automata, known as Vigilus Varlok, emerged from the depths of the Forge-Spire. Its plasma mortar charged with a deadly hum, unleashing blasts of incandescent energy that melted entire squads of Plague Marines into pools of bubbling gore. The Siege-Automata’s weapons were optimized for obliteration, and the massive machine strode forward, its armored hull impervious to most conventional attacks.
Mortarion, seeing the threat posed by Vigilus Varlok, directed his forces to focus on the automaton. Blightlord Terminators, armed with reaper autocannons and combi-weapons, fired salvos of explosive bolts and corrosive shells at the Siege-Automata. Yet, their efforts seemed to only scratch its thick plating. The Blight-Haulers, circling the automaton, unleashed their multi-meltas, aiming for weak points in the armor, while spewing noxious fumes from their bile-spewers in an attempt to corrode its inner workings.
Vigilus Varlok responded by unleashing another volley from its plasma mortar, followed by a rapid-fire burst from its mauler bolt cannon, turning one of the Blight-Haulers into a smoldering wreck. As it reloaded, Mortarion took his chance, soaring towards the automaton with his wings propelling him like a cannonball. He brought Silence down in a mighty overhead strike that cleaved into the automaton's plasma reactor, causing a massive explosion that engulfed both Mortarion and the Siege-Automata.
A Narrow Defeat
The shockwave from the exploding Siege-Automata sent waves of debris and toxic fumes across the battlefield. Mortarion emerged from the blast, wounded and scorched but still standing, his Daemon resilience and Gift of Nurgle sustaining him. The remaining Death Guard forces rallied around their Primarch, pressing the assault with renewed ferocity. Yet, the Mechanicus' defensive lines held firm, bolstered by the firepower of Ironclad Thallos and the disciplined ranks of the Skittari.
A Narrow Defeat
The explosions from the Siege-Automata and the intense back-and-forth firefights had taken a toll on both sides. Despite the overwhelming resilience and supernatural resilience of Mortarion and his Death Guard, the Adeptus Mechanicus had achieved a narrow victory. As the Death Guard’s assault faltered, Helrikkus Kaarn’s voice boomed through the vox channels, his tone emotionless but tinged with an undercurrent of triumph.
“Fall back, abominations,” Kaarn’s voice resonated with cold authority. “Your corruption has no place here. The Omnissiah will not suffer such blasphemy. I shall scour this world of your taint, as one would cleanse rust from iron.”
Mortarion, his voice deep and reverberating like the tolling of a death knell, responded through the battle’s din, his words laced with an unnatural echo. “You speak of rust, Tech-Priest, but your machines are as vulnerable as flesh. I shall return, and the corrosion will run deeper than any of your cleansing rites can mend.”
Kaarn’s mechanical laughter crackled through the vox, the sound hollow and devoid of true mirth. “Return if you will, daemon. We shall be waiting with the tools of your destruction.”
Mortarion, unwilling to risk more of his forces in a futile push, ordered a withdrawal. The Death Guard retreated into the mists of their own making, leaving behind a battlefield littered with the broken remnants of Plague Marines, shattered Blight-Haulers, and the decomposing bodies of their daemonic allies. Yet, the withdrawal was not a simple retreat; as they fell back, the Death Guard seeded the area with virulent spores and toxins, ensuring that every inch of ground gained would carry the risk of death and decay for those who tread upon it.
As the dust settled, Krastellan's Forge-Spires held firm, but the victory was not without cost. The Mechanicus’ defenses had suffered severe damage, and the taint of Nurgle lingered in the very air and soil, turning each subsequent breath into a risk for the tech-priests and their machines.
Resilience and Rot
Following their narrow defeat, the Death Guard regrouped in the corrupted manufactorum district they had claimed in the first battle. The air within their occupied territory was thick with noxious vapors and the constant drone of fat, bloated flies. Mortarion stood atop a crumbling iron tower, his gaze cast across the decaying landscape. His body still bore the scars of the conflict, blackened wounds that wept pus, but his resolve was as strong as ever.
The Primarch spoke with Champion Gorvoth, whose own body had become more grotesque with each passing day, his belly swollen with parasitic growths that squirmed beneath his armor.
“We must press forward, my lord,” Gorvoth rasped, his voice gurgling as if spoken through a mouth full of sludge. “The magisters of the Tainted Choir have discerned a warp-nexus beneath the central Forge-Spire. It pulses with energies that could empower Nurgle’s blessings tenfold if we claim it.”
Mortarion’s eyes gleamed with a dull, green light as he turned his gaze toward Gorvoth. “Yes,” he rumbled, “I have felt it too. But Kaarn and his minions will not yield their sanctum easily. We will need to break them entirely, shatter their defenses, and corrupt the heart of this world.”
He gestured toward the remaining Death Guard forces, many of whom were already participating in the foul rites to bolster their corrupted weaponry and summon reinforcements from the warp. The sound of gurgling chants and the droning buzz of flies filled the air, as new Plaguebearers emerged from the summoning circles and bloated Daemon Engines wheeled into position.
“Prepare the host,” Mortarion commanded. “We shall drown this world in the gifts of our lord. I will deliver this Forge World into the maw of entropy, and no machine-priest will stand against the will of decay.”
The Heart of Rust
The Central Forge-Spire
The third and final conflict would decide the fate of Krastellan. The Death Guard launched an all-out assault on the central Forge-Spire, the heart of the Adeptus Mechanicus’ control over the Forge World. This structure was a massive construct of interwoven steel, plasteel, and adamantium, its towering spires bristling with defense turrets, energy shield generators, and countless cogitator hubs. At its core lay the warp-nexus, a convergence of ancient technology and latent warp energies buried deep beneath the spire.
To defend this stronghold, Helrikkus Kaarn had gathered every remaining warrior and war machine available. Skitarii legions stood shoulder-to-shoulder, while Kastelan Robots and Kataphron Breachers formed bulwarks of mechanical power. The Knight Castellan Ironclad Thallos had been refitted and repaired, its cannons gleaming with newly sanctified oils. Further bolstering the defenses were the newly arrived Legio Krastellan Titans—Horus Imperius, a Reaver-class Titan equipped with a volcano cannon and laser blasters, and Ferrum Purgatus, a Warhound-class Titan armed with turbo-laser destructors and a plasma blastgun.
Mortarion’s forces, swollen by the blessings of Nurgle and the reinforcements from the warp, now included some of the most grotesque and potent warriors and constructs the Death Guard could muster. The Daemon Prince Gloamfall returned, accompanied by a cohort of Nurgling swarms that giggled with unholy delight. Plaguebearers numbered in the hundreds, and numerous Bloat-Drones and Blight-Haulers buzzed and crawled across the battlefield. At Mortarion's command was also a Plague Surgeon known as Morlokk the Seeping, whose unholy ministrations kept the Death Guard’s warriors fighting far beyond mortal endurance.
The corrupted psyker Typhus, Herald of Nurgle, had joined the battle as well, leading his own contingent of Blightlord Terminators. Typhus wielded his signature weapon, Manreaper, a massive scythe encrusted with filth and pitted with decay. His dark magics swirled around him, a shroud of corruption that withered the air itself.
The Initial Assault
Mortarion led the charge, soaring high above the battlefield on his rotted wings. He extended his hand, and the very air around him darkened as he invoked Nurgle’s Rot, a vile spell that spread like wildfire. Below, the advancing Skitarii were enveloped in the greenish haze, their metallic bodies corroding and flesh bloating grotesquely as the contagion took hold.
Champion Gorvoth the Undying, flanked by his Plague Marines, fought with a renewed vigor as they advanced toward the Mechanicus positions. The Plague Marines’ boltguns barked death, firing rounds filled with virulent toxins. Gorvoth’s manreaper, now swollen and pitted with the filth of countless battles, carved through Mechanicus warriors, leaving trails of putrefaction in its wake. His voice, booming through the vox-amplifier in his helmet, taunted the defenders.
“You cannot hide behind your metal bodies forever, machines!” Gorvoth roared as his manreaper cleaved through the chest of a Skitarii Alpha. “Even your circuits shall rot!”
The defenders unleashed everything at their disposal in response. The Knight Castellan Ironclad Thallos roared its defiance, opening fire with its plasma decimator. The superheated energy blasted through the Death Guard’s ranks, reducing Plaguebearers and Nurglings to ash. Horus Imperius, the Reaver-class Titan, strode into battle with its volcano cannon unleashing beams of molten fury, vaporizing Myphitic Blight-Haulers and melting chunks of the very ground into slag.
Mortarion met Horus Imperius in a cataclysmic confrontation. He soared toward the Titan's cockpit, Silence raised high to strike. The Reaver turned its laser blasters upon him, unleashing beams of energy that seared through his armor. Mortarion's invulnerable save flickered and strained under the assault, but he continued forward, gripped by an unholy fervor.
“You dare defy Nurgle’s will, machine?” Mortarion’s voice boomed, filled with ancient malice. “I shall rend your iron hide and let your spirit rust!”
He brought Silence down in a sweeping strike, the scythe's blade gouging a deep scar across the Titan’s chest plate. The impact sent a ripple of necrotic energy through the war machine, causing its systems to glitch and falter momentarily. Seizing the opportunity, Mortarion conjured a psychic pulse of decay, corrupting the Titan's internal mechanisms and spreading rust like wildfire throughout its superstructure.
The Heart of the Forge
Meanwhile, Typhus and his Blightlord Terminators teleported directly into the central spire. They emerged amidst a mass of Skitarii and Tech-Priests, their appearance heralded by a burst of filthy spores that filled the air
A Battle of Scale
The forces assembled at the central Forge-Spire numbered in the tens of thousands, a confrontation that would decide the fate of the entire Forge World. The Adeptus Mechanicus had deployed a significant portion of their remaining military might to defend the spire. Among them were:
10,000 Skitarii warriors, including Vanguard and Rangers armed with radium carbines and galvanic rifles.
1,500 Kataphron Breachers equipped with grav-cannons, torsion crushers, and arc claws.
300 Kastelan Robots in maniples of six, heavily armored and outfitted with incendine combustors and heavy phosphor blasters.
Ironstrider squadrons numbering 200, with Ballistarii and Sydonian Dragoons providing mobile firepower.
1,000 Corpuscarii and Fulgurite Electro-Priests, their bodies crackling with lethal energies, forming a vanguard to counter the daemonic tide.
50 Knight-class war engines, including the towering Knight Castellan Ironclad Thallos and Knight Paladins armed with rapid-fire battle cannons.
2 Legio Krastellan Titans, Horus Imperius, a Reaver-class, and Ferrum Purgatus, a Warhound-class, each with enough firepower to level cities.
The Death Guard’s forces, swollen by Nurgle's dark blessings and the warp's foul gifts, launched an all-out assault with:
8,000 Plague Marines, led by several champions, each wielding a variety of corrupted weapons such as plague spewers, blight launchers, and bolters loaded with virulent rounds.
1,200 Blightlord Terminators, advancing in squads of ten, heavily armored in their ancient Cataphractii war-plate.
4,000 Plaguebearers of Nurgle, shambling forward in rotting hordes, accompanied by 2,000 Nurglings.
200 Myphitic Blight-Haulers and 150 Foetid Bloat-Drones, providing mobile artillery and airborne support.
A dozen Daemon Princes, including Gloamfall, accompanied by hundreds of Plague Drones swooping through the air.
Mortarion himself, commanding the battlefield and wielding his full array of psychic powers, martial prowess, and unholy blessings.
Typhus, Herald of Nurgle, leading 300 Blightlord Terminators on a direct assault into the heart of the central Forge-Spire.
30 Plagueburst Crawlers, lobbing toxic shells that spread corrosive filth wherever they landed.
The surrounding landscape had transformed under the influence of Nurgle’s corruption. Once-pristine metalwork was now tarnished, rusting, and crumbling. The ground was covered in a thick carpet of fetid moss and foul-smelling fungi, while the air hung heavy with the buzzing of flies and the sickeningly sweet stench of decay. Pools of stagnant, oily liquid dotted the battlefield, where toxic sludge bubbled up from deep underground, spreading noxious fumes that burned the lungs of any not blessed by Nurgle.
The Heart of the Forge
As the battle raged on outside, Typhus and his 300 Blightlord Terminators emerged directly within the central Forge-Spire’s sanctum. They appeared in a burst of virulent light and foul spores, warping the air with the stench of rot and corruption. The teleportation had brought them into the midst of the 1,000 Skitarii Vanguard and 300 Tech-Priests who manned the inner defenses, and the air was immediately filled with the crackling of radium fire and the hum of arc weapons.
Typhus, towering over the Tech-Priests and Skitarii, raised his weapon, Manreaper, a massive scythe crusted with grime and corruption. His voice boomed through the halls like a death knell, reverberating off the metallic walls. “Witness the true power of entropy! Your metal limbs shall corrode, your circuits shall falter. Embrace the decay, for it is the fate of all things!”
The Blightlord Terminators followed their dark master’s lead, moving like an unstoppable wave of bloated metal and foulness. Their combi-bolters spat diseased rounds that exploded on impact, spraying caustic filth over their enemies. Blight grenades were lobbed into the Mechanicus ranks, releasing clouds of pestilential spores that choked the life from Tech-Priests and melted the flesh from Skitarii. The Tech-Priests fought back with their arcana and machine rites, unleashing electromagnetic pulses to disrupt the warp energy that clung to the Death Guard, while servitor-mounted plasma culverins burned glowing rents through the ranks of Blightlord Terminators.
Typhus vs. Magos Helrikkus Kaarn
Typhus and his Terminators carved a path toward the heart of the spire where Magos Prime Helrikkus Kaarn awaited. The Magos stood surrounded by his most powerful tech-guard and heavily augmented combat servitors. As Typhus approached, Kaarn’s voice emerged from his vox-unit, a grinding, metallic hiss.
“I know you, Typhus of the Death Guard. You were once a warrior of flesh and bone. Now you are nothing but a vessel of decay, a broken thing wearing a god’s chains.”
Typhus grinned beneath his rusted helm, his eyes blazing with malevolent green light. “I wear the blessings of Nurgle as my armor, machine-slave. It is you who are broken, clinging to a false god that cannot protect even the simplest of your circuits. Today, you will learn the futility of resisting decay.”
Kaarn’s servo-arms lashed out, wielding a power axe that crackled with disruptive energy fields and a volkite serpentia that spat lances of searing heat at Typhus. The Herald of Nurgle countered with the Manreaper, the scythe’s blade glowing with unholy power as it clashed with Kaarn’s axe. Each swing of Typhus’ weapon released a burst of necrotic energy that corroded Kaarn’s augmetics and seeped into the metal floor, leaving trails of rust in its wake. Kaarn retaliated by activating his neuro-phage emitter, a device designed to disrupt the nervous systems of organic beings and even daemon forms. Typhus stumbled back as the waves of disorienting energy washed over him, briefly dulling his senses.
“You see, rot-bearer?” Kaarn intoned. “Even your blighted god cannot overcome the purity of the Omnissiah’s will.”
The Tech-Priest's moment of triumph was short-lived. Typhus gathered his psychic power and invoked the Curse of the Leper. The power surged through the air like a foul wind, warping the very atoms around Kaarn and his retinue. Flesh and metal alike bloated and split, the Tech-Priests’ augmetics began to fail, spewing black oil and diseased coolant. Kaarn’s limbs twitched uncontrollably as the corruption spread, and he staggered, his neuro-phage emitter sparking and failing.
“Fool,” Typhus sneered as he advanced, swinging the Manreaper in a deadly arc that severed Kaarn’s primary servo-arm. “There is no will but Nurgle’s will.”
With a final strike, Typhus drove the Manreaper into Kaarn’s chest, splitting the Tech-Priest from shoulder to hip. The Magos collapsed to the floor, his eyes dimming as the corruption ate away at his remaining augmetics.
The Battle Outside: Titans and Daemons
While Typhus claimed victory inside the spire, the battle outside intensified. The massive Titans, Horus Imperius and Ferrum Purgatus, continued their relentless bombardment of the Death Guard forces. The Reaver-class Titan’s volcano cannon melted swathes of Plaguebearers into steaming sludge, while the Warhound's turbo-lasers swept across the battlefield, vaporizing Nurglings and obliterating corrupted war machines.
The environment had become a surreal landscape of chaos. The once-smooth metal ground was cracked and cratered, and the Forge-Spire's walls dripped with foul fluids that ran like diseased veins. Mortarion, flying above the carnage, invoked Gift of Contagion once more, saturating the air with a virulent haze. The Titans’ sensors began to falter as corruption seeped into their systems, warping targeting cogitators and causing malfunctions.
Gloamfall, the Daemon Prince, took to the sky alongside a dozen Plague Drones. The Daemon Prince soared towards Ferrum Purgatus, his warpsword blazing with green fire. The Warhound Titan retaliated, its plasma blastgun firing a bolt of incandescent energy that struck Gloamfall’s chest, sending him hurtling backwards. The Daemon Prince's resilient form began to heal almost immediately, the wounds sealing up as Nurgle’s blessings coursed through him.
“You cannot slay what is eternal!” Gloamfall roared, diving again toward the Warhound.
Gloamfall's Assault on Ferrum Purgatus
Gloamfall's warpsword plunged into Ferrum Purgatus’s cockpit, the blade's corruptive energy surging through the Titan’s systems. Sparks flew as the Daemon Prince tore into the machine, his talons ripping out vital components and tearing through armor plating. The Warhound Titan staggered as its servos groaned under the weight of the corruption spreading through its circuits. It managed one desperate swipe with its chainfist, but Gloamfall was already moving, his wings propelling him upward in a burst of speed. With a final heave, he drove his warpsword deep into the Titan's reactor core, unleashing a torrent of daemonic energy that detonated the massive war engine from within. The explosion tore apart the Warhound in a fiery blast, scattering molten debris across the battlefield.
As the Warhound fell, its wreckage aflame and smoking, the environment responded to the intense conflict. The corruption of Nurgle spread outward like a living tide, consuming the debris. The ground itself seemed to buckle and bleed, bubbling with noxious fluids that seeped from the earth, while the Forge-Spire's walls groaned under the pressure of the warp energies saturating the air.
Mortarion vs. Horus Imperius
Meanwhile, Mortarion continued his cataclysmic confrontation with Horus Imperius. The Reaver-class Titan unleashed another volley from its laser blasters, the beams searing through the atmosphere and gouging deep furrows into the ground. Mortarion’s form blurred as he dodged and weaved through the barrage, his wings carrying him upward in a spiraling ascent. As he closed in, he drew on his psychic powers, invoking Curse of the Leper once more. The power swelled around him, a toxic miasma that seeped into the Titan’s systems, spreading rust and decay across its armored hull. Servos locked up, targeting arrays malfunctioned, and the machine spirit howled in dismay.
“You cannot stop the rot,” Mortarion intoned as he swooped down towards the Titan's weakened chassis. “Entropy is the only certainty.”
With a mighty swing, Silence cleaved through the Reaver’s power conduits, sending arcs of electricity crackling into the air. The Reaver stumbled backward, its footing unstable as Mortarion pressed the attack. Using The Lantern, Mortarion fired a concentrated beam of warp-tainted energy into the heart of the Titan, blasting apart its control center and sending the towering war machine toppling to the ground. The fall of Horus Imperius shook the battlefield, a deafening crash that reverberated through the very walls of the Forge-Spire.
The Last Stand of the Mechanicus
Inside the spire, the situation was growing dire for the defenders. With Magos Prime Helrikkus Kaarn slain and Typhus carving a path toward the warp-nexus, the remaining Tech-Priests and Skitarii struggled to hold the line. The Skitarii Vanguard, now down to only 3,000 warriors, fought in desperate squads, unleashing bursts of radium fire and charged arc shots in an attempt to slow the advancing Blightlord Terminators. Combat servitors armed with plasma culverins and powerfists rushed forward, their attacks fueled by last-ditch programming, while Tech-Priests activated the spire’s final defensive measures—automated turrets and graviton pulse emitters.
Typhus, his armor soaked in the filth of battle, laughed as he saw the defenders’ efforts. “You only delay the inevitable,” he mocked, swinging the Manreaper in great arcs that dismembered servitors and split open Skitarii. “Your god of machines will rust, your sacred forges will fall silent. This world will become a garden of decay!”
“Then we will die as warriors of the Omnissiah,” one of the surviving Tech-Priests declared defiantly, leveling a volkite blaster at Typhus. “We do not fear the end.”
The Warp-Nexus and Mortarion’s Dark Ritual
As Typhus and his Blightlords reached the central chamber, the warp-nexus itself pulsed with raw energy. The nexus appeared as a swirling, iridescent maelstrom of warp-light, contained within a complex array of ancient machinery and arcane circuits. Its power was immense, its presence tugging at the fabric of reality itself, and Typhus could feel the raw warp energy radiating from it, a feast of corruption that could fuel Nurgle's blessings tenfold.
Mortarion, his wings folding behind him as he entered the chamber, spoke a single word, his voice reverberating through the nexus chamber. “Begin.”
Typhus and Morlokk the Seeping, the Plague Surgeon, stepped forward and began the dark ritual. Their chants echoed throughout the chamber, invoking Nurgle's name in the foulest of tongues. The nexus reacted, its energies drawn into Mortarion as he focused his psychic powers upon the swirling vortex. The room filled with a sickening green light as the nexus’ energy was channeled into a cataclysmic wave of warp-corruption. The ground split open, and from the gaping cracks, foul tendrils of diseased flora and rivers of bile surged forth, covering the walls and machinery with festering growth.
The Climax – Kaarn’s Final Gambit
Just when all seemed lost for the defenders, a hidden failsafe activated. Magos Kaarn’s last command echoed through the spire’s systems—a final protocol designed to sever the warp-nexus from the material realm. The machinery around the nexus began to glow with an ominous red hue, and a resonant hum filled the chamber. The device would collapse the nexus upon itself, sealing away the warp energy but destroying the entire Forge-Spire in the process.
Mortarion felt the shift in the warp and understood the Tech-Priest's final gambit. With a snarl, he redoubled his psychic efforts, attempting to wrest control of the collapsing energies. Typhus joined him, focusing his dark powers on stabilizing the nexus long enough to complete the ritual.
“You seek to destroy what you cannot defend!” Mortarion roared, his voice shaking the walls. “But even in your death throes, you only bring about the inevitable decay.”
The Final Outcome
The tension built to an unbearable level as the nexus pulsated, caught between collapsing and releasing its energy in one last explosion. The spire’s walls cracked, and the floor buckled as Mortarion fought to control the volatile warp energies. Finally, with a guttural shout, Mortarion poured his will into the nexus, and with one last surge, the energy was released—not as a destructive explosion, but as a wave of corruption that swept outward, enveloping the entire spire.
The Adeptus Mechanicus within the Forge-Spire were consumed by the wave. Their metal and flesh dissolved into filth, and their machinery crumbled to dust. The once-mighty central Forge-Spire fell silent as its structure decayed, collapsing in on itself, leaving nothing but a rotted ruin.
Epilogue: A Garden of Decay
Krastellan had fallen. The central Forge-Spire, once a beacon of the Omnissiah’s light, lay in ruin, consumed by Nurgle’s touch. The corrupted landscape around the spire continued to grow, withered flora blooming in grotesque beauty. The air itself seemed alive with decay, and pools of stagnant water, thick with slime and pestilence, dotted the land.
Mortarion stood amidst the ruin, victorious but pensive. He looked out over the corrupted wasteland, his gaze distant as if seeing beyond the material realm.
“The Omnissiah's light has flickered and died,” he murmured. “And this world shall rot forevermore.”
Champion Gorvoth approached his Primarch, his grotesque form even more bloated and warped than before. “The Forge World is ours, my lord. The victory is complete.”
Mortarion turned his gaze to his champion, a faint smile curling behind his rusted helm. “Yes, but the war is never complete, Gorvoth. There is always more that must be reclaimed by the inevitability of decay. This world is merely the beginning.”
The victory on Krastellan would serve as a dark testament to the power of decay, a warning to the Imperium that even the mightiest of worlds could fall to the plague. As Mortarion prepared to leave the rotting remains of Krastellan behind, he knew that there would always be more worlds to claim in Nurgle's name. The Plague Ascendant would continue, spreading entropy and suffering across the galaxy, one fallen world at a time.
Note from the CodexMaledictus:
As you reach the end of The Plague Ascendant: The Fall of Krastellan, reflect on the tale's weaving of decay, inevitability, and the grotesque beauty of entropy. This account showcases Mortarion's harrowing mastery as a psyker, daemon, and warlord, embodying Nurgle’s relentless will as he leads his festering legion through the war-torn Forge World. The story highlights the iron resolve of the Adeptus Mechanicus, clashing against the insidious corruption of the Death Guard, all while exploring the psychological unraveling of warriors trapped in a war that promises only rot.
Themes of perseverance, the cost of devotion, and the blurring line between machine and mortal are interwoven through the core battles and dialogue. I welcome your thoughts, critiques, and requests for future tales of war, glory, and the dark forces that shape the 41st millennium.
For those drawn to the grim and the inevitable, come back and let your curiosity lead you through future chronicles. After all, decay waits for no one, and the CodexMaledictus is never short of tales to tell.