Admu and Mekegare tumbled and hurtled through the dark, smashing against metal support beams and struts. The inside of the vast superstructure was like an immense, dark forest of steel and concrete, anchored to the rocky substrate far below. Mekegare would try to cling to the walls and supports, but Admu would tear him away. Admu would attempt to take flight and arrest her fall, but Mekegare would simply pull her down with his oppressive bulk. They fell through layer after layer until finally they reached the deepest, innermost chamber of the Hold. They crashed through the ceiling and landed in a reservoir of cold water. Their surroundings were lit by a red haze of geothermal energy, veins of churning orange magma funneled into a large chamber in the center of the cooling pond. This was the center of the Hold's hearth, a beating dynamo fed by the energy of the planetoid itself. Admu lifted herself out of the shallow water and turned her head, beholding an immense shape suspended in the darkness. Locked up in warp-crafted chains, secreted away in the heart of the hold, she saw an impossibly huge spherical construct, covered in chiseled visages and sprouting innumerable wires and cables. It looked like some kind of mechanical plant or organ, connected by its roots and tendrils to the entire planet, yet it was currently cold, dead, and silent.
Before she could observe any further, Mekegare burst from the water in a fit of rage.
"You arrogant… presumptuous… insolent pretender!" Mekegare said, seething with anger. "You think that you are special? That only you can harness power beyond your domain? That your… anomalous nature makes you better than me!? I was created by Nurgle to transgress outside of his domain, to transcend beyond his boundaries! I am no mere Plaguebearer, I am a pox on every machine, a curse upon the material world itself! This Hold… these machines… EVERY machine… is MY domain. MY birthright. You think that by absorbing… a modicum of my accumulated power… that you can surpass me? Allow me to show you, dearest sister, my true power!"
The daemon's skin began to glow with a sickly aura, fumes of luminescent warp energy radiating from his bloated form. The magma chambers that surrounded them began to grow brighter, and a low rumbling shook the floor. Several streams of glowing orange-red energy burst from the walls, piercing the daemon's hide and flowing into his body. The tendrils of power coursed with primordial strength, emitting a shockwave of heat and pressure so powerful Admu was pushed back and unable to approach it. The daemon transformed before her eyes, twisting and reshaping itself as it drank deep from the near-limitless well of geothermal power. Its myriad of spindly and asymmetric legs withered and fell away, crumbling into dust and ash in the intense heat until it was left with only its strongest 4 arms and 4 legs. The rust and corrosion that blanketed its metal plates and limbs vaporized, leaving behind only polished, tempered daemonsteel. Its sickly, rot-eaten flesh burned away, and its formerly malnourished muscles bloated and stretched like taut rubber with a reddish-brown leathery complexion. The daemon's face contorted and stretched into a lean, angular form, looking less like a bloated corpse and more like a fearsome predator. The more power it drew in, the less and less it seemed to display the characteristic traits of a spawn of Nurgle, forgoing fidelity and fealty to its god in favor of pure, raw, daemonic strength.
The shockwaves finally ceased, allowing Admu to get her footing. Mekegare raised his newly rejuvenated arms upwards, clenching his fists and flexing his hypertrophic musculature. Steam rose in thin clouds all around him as the ambient heat he emanated touched the cool water. He strode forward, thin bolts of crimson energy arcing from his body. Admu rose out of the water with her eyes locked on the daemon's, her body tense and prepared to strike. Before she could make the first move, Mekegare burst forth on his strengthened legs and lunged at her with his largest claw. The serrated edge grazed her arm as she dashed out of the way, with daemon grinding to a halt and quickly shifting his trajectory. The tips of his mechanical legs clanged furiously against the wet metal floor as he sped towards her, snapping and striking at her with his fists and claws. Admu shifted her head to dodge a punch, then responded with a forceful jab of her own. Her fist struck the daemon on his chin, snapping his head backwards. He quickly recovered, and when Admu attempted to strike a second time he grabbed her fist and intercepted it.
He flung her across the room, sending her tumbling through the water until she dug her talons into the ground and arrested her momentum. Mekegare leapt into the air with surprising agility, nearly slamming down on top of Admu as she rolled out of the way and creating a sizable crater in the floor. In an instant she unfurled her wings and shot into the air but found herself stopping mid-air. Mekegare had grabbed onto her tail, swinging her against the ground with spiteful laughter. She grimaced as she smashed against the concrete floor, leaving a web of cracks beneath her. She attempted to dig her claws in, but the daemon dragged and swung her around before flinging her through the air into a rough-hewn stone wall. She opened her eyes to see the daemon already caught up with her, lunging forward with his claw. Determined to strike back, she quickly wrapped her arms around the oversized limb and dug her talons into the ground. She swung the daemon's arm and his immense body along with it, sending him crashing into the rock face. Mekegare broke free of her grasp, and she dashed away to avoid his swiping claws. His four legs staggered as he regained his footing. An expression of rage flashed across his face, and the daemon turned to the stone wall behind him. He dug his four arms into the rock, tearing out an immense chunk of solid stone and lifting it over his head. He flung the giant boulder at Admu, but she simply dug her feet into the ground. She thrust her head into the oncoming projectile, and with a blast of thunder her ethereal antlers shattered it to pieces.
In the split second between impact and the scattering of stone debris, Mekegare struck. His fist struck Admu square in the chest, knocking her backwards several meters. The two engaged in a brutal clash of fists, claws, and talons, their movements and strikes flying at incredible speeds despite the immense weight and power both wielded. Talons slashed through metal and muscle, claws dug into flesh and fur. Admu fought like she had never fought in her life, a primal fire burning in her chest that compelled her to strike harder, more savagely. Mekegare had become a berserk avatar of daemonic power, resembling more and more a daemon of pure chaos than a servant of Nurgle as the fight went on. After several minutes of brutal exchanges, they locked arms in a contest of strength, with Admu grappling Mekegare's largest arms with her own and his two smaller appendages with the talons on her wings.
They pushed against each other with all of their might, the air itself between them seeming to crackle and spark with ambient warp energy. Then, Admu had an idea. Her tail began to flare up with orange-gold flame, and she whipped it across the daemon's chest. Mekegare winced at the scorching wound across his chest and relented for a single moment, allowing Admu to gain the upper hand. She threw open his arms and dug her claws into Mekegare's chest and abdomen, then mustered all of her strength into lifting the colossal hulk off of the ground. Mekegare's legs futilely thrashed in the air, but it was too late. The muscles in her arms and torso flex tightly as Admu lifted the massive daemon above her head, then slammed him straight into the ground. The floor buckled from the impact, sending cracks shooting out in all directions. Mekegare weakly struggled to lift himself, the sheer weight of his empowered form becoming a weakness. Admu panted with a savage look in here eyes, walking over to the fallen daemon and stomping on its chest. Her talons dug into the metal and flesh, and she grabbed the daemon by the horn. She balled her hand tightly into a fist, striking it in the face with thunderous force. Then she punched him again. And again. And again. She struck him until her knuckles began to bleed, and then she continued punching.
Finally, the horn she was gripping snapped off. Mekegare's head struck the floor with a loud thud, his entire body lying motionless on the ground. The daemon's metal mask was dented and partially split down the middle, blood and daemonic ichor oozing from its cracks as its battered, toothy maw hung open. Admu's bloodied and bruised hand fell limp by her side, and she tossed the daemon's horn aside. Admu pulled her talons from the daemon's flesh and stumbled backwards, the exhaustion and accumulated damage beginning to register as searing pain all over her body. Despite this, the fire inside of her still raged. Something within her boiled and seethed, a deafening howl in her soul that filled her skull with the throbbing noise of rushing blood. She gripped her head and closed her eyes in discomfort as the migraine racked her brain. Then, her eyes shot open as she quickly spun around to see a looming figure towering over her. Before she could react, Mekegare seized her by the neck and slammed her down. He brought both his arms down on her abdomen in a single strike, and her arms and legs shot upward reflexively. The air rushed out of her lungs and the pain made her head swim. The daemon grabbed her by the shoulder, digging his claws into her flesh, and savagely threw her against the wall.
As she struggled to remain on her feet, Mekegare planted his metallic legs into the ground and thrust out his chest. The metal plates on his body began to glow red-hot and steam billowed around him as the ambient temperature quickly rose. He gathered all of the accumulated power he could muster and compressed it, then releasing all of it in a single, concentrated burst. A white-red beam of scorching energy burst from the daemon's maw, instantly vaporizing the water around it. The entire, cavernous chamber was consumed by blinding light, followed by a thunderous shockwave that nearly knocked the daemon off of its feet. Chunks of rock and debris fell from the ceiling, splashing into the churning, near-boiling water below. Immense clouds of steam hung in the air, and the water that wasn't vaporized by the blast fell down like a drizzle of rain. Mekegare's legs buckled as he tried to recover from the immense expenditure of energy, his body weighing down like it was made of pure lead.
"Finally…" The daemon said through labored breaths. "...Decades of accumulated energy… wasted." He said, growling with frustration. "No matter… now that this matter is resolved… I can spend another few decades regaining my strength. What's a century or two to a daemon of Nurgle?" He chuckled.
The daemon turned around slowly, his mechanical legs plodding through the still-turbulent waters.
"Now… to go dispose of the remaining intruders-" he said, before freezing in his tracks.
A strange look flashed across the daemon's face. He looked down at his mechanical claw, which, for some reason, was beginning to shake uncontrollably. A chill ran through his entire being, and for a moment, it felt as though his heart had stopped. In a slow, jerky motion, the daemon turned his head to the steaming crater where he had thought his enemy was vaporized. His eyes widened with something beyond fear, an emotion he would have thought entirely foreign to daemonkind before this moment. His limbs hung in the air, gripped by a primeval instinct that refused to let go of him. His warp-born mind was cast back, back into the depths of time, back to a time before conscious thought. Before daemons. Before Gods. When there was no order to differentiate from Chaos in the primordial churn of Nature's cauldron. Sensations shot through him, lingering remnants of a time before consciousness, the fragmented pieces which would eventually form the first of daemonkind.
That was what burned through Mekegare's mind as his eyes stared into the mist, at the burning rings of green gold that stared back at him. Her form was that of a feral wraith, nothing but teeth, claws, fur, bone, and horn. A hunched animal figure wreathed in shadow, a bestial avatar of that primordial darkness that consciousness emerged from. There was no trace of humanity, no malicious intent, no conscious anger. The earliest fear, the first fear that ever gripped a conscious mind. A predator.
And he was its prey.
"You… you're not… a daem-"
It was all that Mekegare had the opportunity to say before she struck. In the darkness, the glint of white teeth shone. A moment passed before the fangs sought flesh to tear. Mekegare tried to react, but he was far, far too slow. In an instant the full weight of her body struck the daemon as she pounced like a wild tiger plunging its claws into an injured deer. Admu's fangs sunk into the sides of his face, her maw encompassing the daemon's head until he could see nothing but the blackness within her elongated muzzle. He screamed in unimaginable pain as the metal tore from his flesh, peeling away and leaving raw muscle and streams of blood. Admu leapt backwards and tossed the metallic face from her mouth, staring with the same cold, unnerving predator-gaze. Mekegare stumbled backwards and clutched his skinned face, then roared in anguish. He thrashed at her with his claw, landing straight in her taloned grip. With one, swift motion she twisted the arm by one complete turn, tearing metal and flesh, rupturing muscles, and exposing bone. Blood shot out in a multitude of tight, pressurized streams, spraying across Admu's face. Mekegare swung with his other large arm out of frenzied instinct, and she tore it from its socket. Blood gushed from the open wound.
Mekegare stumbled backwards as Admu stalked forward with a slow and deliberate pace. She grabbed one of his legs and pulled it out from under him, knocking the daemon on its back. She tore the mechanical limb out and crushed another underfoot, crippling the hulking daemon. Mekegare tried to weakly resist with its two remaining arms and legs, but Admu simply unfurled her wings and leapt on top of the fallen daemon. Her talons pinned its two remaining arms, and the claws on her wing dug into his mutilated face. The daemon could do nothing but flail impotently and make a rumbling, gurgling noise from its slashed throat. Her fangs and claws dug into its armored chest, rending metal from flesh and flesh from bone. She shoved her hands into the daemon's exposed rib cage, wrenching it open with a sickening snap of bone as Mekegare wheezed and squealed in agony. She buried her toothy maw into the daemon's chest cavity, ripping out steaming organs and entrails until her prize was laid bare. She raised her clawed hand and plunged into the daemon's chest. Hung with metal tubes and fleshy arteries, she pulled the daemon's still-beating heart from its body and raised it into the air. She gripped the organ in both hands and shoved it into her face, tearing into the meat with her dagger-like teeth. She devoured the heart like a starved hyena, leaving nothing behind but the blood dripping from her face.
Mekegare's life was extinguished, devoured in body and soul. All that remained was the rapidly-decaying husk that lay motionless in the water. Admu's cold and predatory eyes faded as the fire inside of her was quenched. Her limbs fell heavy at her sides as she stumbled backwards, her eyelids drooping with exhaustion. She faltered through the knee-deep water, swaying with fatigue. With each step, chunks of bestial daemon-flesh sloughed off from her shadowy form, falling into the water and quickly disintegrating into warp energy. When at last she had reverted to her original form, she fell face-first into the cooling reservoir, unconscious.