From the journals of Midas Mitarion, Chapter Master, Gilded Aquilas, 0 358.030.M42
The world beneath us was lifeless. The landscape was scorched, burned clean of all semblance of life. What had once been a world of science and progress had been deliberately devastated by the Imperium upon the cessation of active hostilities. They could take no chance that those who came before us were not fully corrupted by the Primarch whose gene-seed we were based off of. He had told me what he know of them - a charismatic individual who soon fell to serpentine seductions and abandoned his oaths to his Father.
We had come from Aurumios to examine what was left of the structures on Chemos, some of whom's structures still remained in fragments, concrete slabs of foundations jutting from the surface of the desolate world. Our dropships gracefully descended to the surface of the world, which still held an atmosphere - one whose deathly taste still filtered through the purifiers of my helmet. Soon, we landed near the ruins of the ancient fortress-monastery, crumbling remains of decayed gold and splintered marble scattered across the landscape as I was the first to emerge upon the surface of the fallen planet.
Though a cleansing of fire had ensured that nothing of Chaos remained visible from orbit, a wrench in my gut still took hold - a sign of some sort of trouble, still held within the orbitally bombarded ruins. Sergeant Iconos soon followed, Brother Pietas leading up the rear. We took lead of the chapter's forces, nine hundred and twenty-three battle-brothers in total, traveling towards the building's carcass. The last of us to descend crashed to the ground with a thump, the feet of the Contemptor Pattern Dreadnought crushing the ground beneath him further into cinders. When we had been formed, I had been told that we would receive a blessing to further give us knowledge from the ancient times, before our father turned to Chaos. While the Contemptor had given much insight into the traditions and customs of our forefathers, it seemed to be deliberately hiding its true identity.
"The opportunity is at hand for vengeance." Pietas stated, gilded armor polished to a fault over weeks of laboring by the chapter servitors. To not fall into the trap of perfection, he was sent through the same trial as all other battle-brothers. When the effects of the gene-seed began to wear away, when he desired of his own free will to replace the bespectacled plate with mere painted ceramite - then would he be ready for further advancement through the chapter's hierarchy. "For us to take another step on the path to perfection our ancestors deviated from."
"I see the gene-seed still has hold on you, Pietas..." Iconos responded - the only portion of his armor that remained gilt was the prominent Aquila on his chestplate, and soon he would be rid of that as well. We did not wear the winged skull of other chapters. The Aquila was always something special to us, something that we always held closer than a genericized symbol. A way for us to, even in these dark times, be reminded of our Father, the Emperor.
"My armor is the epitome of Astartes plate. I am extraordinarily close to true exemplary." He responded with a characteristic haughty attitude - all new Astartes had them, and it was expected that they would, in time, grow out of it and understand more of their purpose.
"That is what you do not understand, Brother." Iconos corrected him. "Perfection does not come from purity seals or the level of gilding applied to your armor. Perfection comes from knowing that your duty to the Imperium and its citizens is the righteous duty our Father demands of us. Our forebears forgot this - we shall not."
Further forward we marched, through what had once been beautiful arches, part of a grandiose pathway leading to the heart of the fortress-monastery. Now they remained silent, not even carcasses remaining. Yet the feeling of an unnatural presence here still remained. The Contemptor followed behind us as we reached what had once been the heart of the building - yet here nothing remained but fragmented shards of concrete.
"There is something here." With a rotation of its Kheres Assault Cannon, and a flurry of shells, a section of what had once been the floor collapsed, exposing a chasm beneath our feet. As the rubble settled, we gazed into the crevasse, eying a section of tunnel that would have run underneath the very depths of the fallen fortress. Movement briefly showed itself down beneath the tunnel before disappearing, a faint purple light exposed to the elements.
I led my supporting battle-brothers down a thin ridge on one side of the crack, the rubble having formed an exceptionally steep slope. Brother Demetrius was the only one of us to fall, his impact on the bottom of the detritus resonating with a loud clang before he slowly stood up. "Merry drop, was it?" The helmetless Iconos smiled as he looked at the fellow Gilded Aquila, plate heavily scuffed and scratched by the rock.
"Pleasure as always, sir." Demetrius gave a nod before turning back towards the tunnel opening, whose glow was now far more visible to us. Steady steps proceeded as the Contemptor followed us down, flattening the top of the mound with each step. I motioned to the others at the ridge to remain there - one had no idea what could attempt to overwhelm us.
We stepped further into the tunnel, light radiating within - a sickening light, unnatural in coloration. Inhuman sounds began to shriek from the malevolent cocktail of color further down the hall. Something was very wrong - and soon we discovered why.
A coven of Chaos worshippers were gathered in a circle - their flesh was inhumanly pale, irises nonexistent as they gazed into an intricate summoning circle, their shrieks organized in a perfect crescendo. This was a ritual most foul, and my power sword was soon raised as I charged forward.
A blinding light radiated, bright enough to leave our eyes in darkness as we found ourselves stunned by the sudden shock of nigh-perfection. All who had surrounded the circle were no more, their flesh and bone melting together, shifting and splintering like some inhuman golem as a serpent-like form began to coalesce. Four arms soon forced their way from the creature's torso, a horned head with penetrating eyes gazing back at us.
"Primarch." The dreadnought aimed its cannon at the daemonic entity that had once been a child of the Emperor.
"Rylanor." The voice echoed, a ripple in its tone. One could faintly make out the voice of the true Fulgrim before it was drowned out in a mesmerizing cocktail of echoes and alterations. "And here I expected that you had died during the Istvaan incident. How unfortunate. And it seems you found yourself more loyalists to beguile with the nonsense about loyalty to my father."
"You have never been what you once were since the day you took that blade." I remained silent, sword ready for action if and when it was needed.
"The blade was nothing more than a tool to my enlightenment. Now I have become something more - a student of limitless pleasure unknown by mere mortals. My domain is mine alone to shape as I please - who are you to claim any different?" Such a level of arrogance was beyond even that of a freshly forged scout.
"Do not seek to rationalize your deeds. Your hands are wrought with the blood of your brothers, and you shall not succeed with your plans. Not so long as I can function."
"Pah." The serpentine creature spat towards the construct, acidic venom etching a new gouge in its plate. "The last of my followers in the Materium have given me new life here. With you and your playthings gone, I shall have a galaxy to claim - a galaxy that even the so-called 'Warmaster' cannot take. I will bring my patron's ecstatic grip to every corner of the galaxy. Those who resist shall become new sensations to experience. Those who join me shall be rewarded with pleasure beyond their wildest dreams."
"Enough, daemon!" Iconos growled, bolter at the ready as he aimed it at the head of the beast. "Your foul whispers shall not pollute the minds of the Emperor's sons. Never again shall we be bewitched by such temptation!"
"How cute... The little sergeant seeks to deny me what I may take at any moment - but very well." With the cut of a blade, a rift was opened within the Warp, the ear-piercing noise of possessed sonic weaponry resonating as a group of Emperor's Children -our fallen predecessors - emerged. "My children shall deal with you until there is but one left - I shall savor his sensations personally."
We struggled against the chaotic warriors, beings with millennia of experience more than our time spent in the field combined. Despite this, we engaged the foul knaves in combat. A good deal died as we continued to fend off the ever-growing horde, nonwe of us able to contact our fellow brothers to gain their assistance.
Then Iconos fell. A mighty blade jutted through his abdomen, piercing straight through his armor as he soon found himself on his knees. Fulgrim had impaled him from behind with a horrifying weapon - a weapon that seemed so familiar.
"Enough!" With a grasp, Rylanor lurched forward, knocking the Daemon prince back and leaving the weapon impaled through the Sergeant's spine as both began to battle. Where marks from his daemonblades made contact with the Contemptor's chassis, spots of corrosion began to form - the same occurred around the entry and exit wound of the barely breathing Iconos. His gun was raised, and as he breathed his last, a round exited the barrel of his bolter, traveling into the flesh of the fallen Primarch as he screamed in sensation.
I removed my blade from the eye socket of another traitor marine. Pietas held his own as I turned the field generator on my blade to as high a setting as I could reach, bringing the weapon down upon the sword that had murdered not only a fellow Gilded Aquila, but a friend as well.
A splinter of the weapon soon shaved itself away from the larger blade, and I found myself grasping it, throwing it in a blind rage at the creature. Something opened, another warp gate forming across the one Fulgrim has summoned, the gates tearing one another to pieces in an inhuman way. He screamed a cry of what I figured to be pain or pleasure as Rylanor sent a great many rounds from his assault cannon through the daemon's chest. A close combat weapon plunged forward, piercing entirely through the body of the fallen Primarch even as two of his swords speared through the crew compartment of the Contemptor. The look on Fulgrim's face was a pure ecstasy before eyes closed and the body began to melt away, returning to the corrupt remains of cultists as it had once been.
"Cha... Chapter Master..." Pietas slowly stood to his feet, a hand liquified by the power of daemonic sonic weaponry. "I... Is this why we must remain quiet?"
"Yes. There is the potential for evil in everyone. We must deny ourselves it, unlike our fallen forebears."
"What can I say?" He spluttered. "We are doomed to suffer that monster's attention for eternity! Forever will he continue to try and force us into his fold... We will lose men by the hundreds to Slaanesh."
"Have faith, Pietas. Have faith. Things shall be better one day. I may not be here to see it, and neither may you, but mankind shall one day experience the perfect future our Father had planned for it to know. All will be right with the world then - but until that time, we must continue to perform what duty is demanded of us."
His head lowered in contemplation before he responded. "Chapter Master... I wish to undergo the Degilding upon return to Aurumios."
"You will be undergoing it here - we must protect this world from another such incident. It is only best for mankind."