Though the Alpha Legion was fractured almost literally into a thousand pieces, it remained much like its heraldic crest, the multi-headed Hydra; despite vastly different scales of operation, shifting objectives, and even questionable loyalties, the scattered warbands maintained their clandestine connections.
For most of the younger warriors, including the likes of Solomon Akurra, the chance to look upon the radiance of their Gene-father was a mythic impossibility. Only the ancient veterans, the "Long War" survivors like Drazus, could remember a time before the Great Betrayal.
Yet, the resonance within their gene-seed was instantaneous. Every Alpha Legion Astartes of the Serpent's Teeth warband fell to their knees in immediate, instinctive submission.
"The Hydra shall be made whole... Alpha shall restore its former might. Summon my progeny."
Omegon's voice was steady and measured, devoid of overt emotion. The Alpha Legionnaires, trembling with a mix of shock and fanatical devotion, looked upon the Master of the Hydra with profound reverence. They burned with questions regarding how their Gene-father had returned from the shadows of history, yet none dared voice such an overstepping inquiry.
"It shall be done, Father. I will contact all points immediately!" Drazus declared. He turned to Krozier Va'kai, the Captain of the Whisper, the flagship shared by Akurra and the Serpent's Teeth, and barked an order: "Issue the muster signal to every warband within Segmentum Ultima. Convene the Council of Truth—proclaim to them that our Gene-father has returned. The Alpha Legion shall be great once more!"
"Understood!"
Every Astartes present felt a surge of electrification. Akurra, in particular, was consumed by fervor; he had long sought to reform the Legion's structure, loathing the way they scurried through the Imperium like insects in disconnected, aimless cells.
In the original timeline, Akurra had managed to rally half the galaxy's Alpha Legionnaires using only the shard of Omegon's Pale Spear to form the Ghost Legion. Now, with news of the Primarch's physical return sweeping through the warbands like a tsunami, even those cells that had previously scoffed at Akurra's relics found it impossible to remain aloof.
Across the Segmentum Ultima, Alpha Legion warbands began to converge upon their secret rallying point: the Unseen Fortress.
A gathering of this magnitude had not been witnessed in ten millennia. Because the Legion had devolved into warbands, which split into cells, which further fractured into sub-cells, it was common for two Alpha Legion agents to pass one another on a Hive spire walkway without so much as a glance, each entirely unaware of the other's existence. Every cell wore the mask of Imperial loyalists, and just as often, accused their brothers of being true loyalists while engaging in fratricidal shadow wars.
…
Within the Unseen Fortress, the premier hidden stronghold of the Alpha Legion in the Segmentum Ultima, the Serpent's Teeth arrived in the wake of Omegon. The resident agents stationed there were broken by the sheer metaphysical weight of the Primarch's presence; the moment they laid eyes on him, their blood sang, and they knelt before their Gene-father.
Omegon sat upon the high throne of the briefing hall. Drazus, Akurra, and the rest of the Serpent's Teeth stood behind him, acting as a grim honor guard, their chests swelling with pride. With every passing Terran hour, entirely new cells and warbands, groups they had never heard of or seen, filtered into the hall to swear their fealty.
"What did I tell you? My intuition is never wrong," Drazus remarked smugly to Akurra as yet another renowned warband, numbering over a thousand Astartes, pledged their lives to the Primarch.
"Indeed. I should never have doubted you, my Lord. Thanks be to the Emp—no, bah! Praise be to the Primarch. Our Legion is finally being reborn," Akurra replied, forgoing his usual reticence to pray openly.
Drazus, however, found his mind drifting back to the Battle of Pluto ten thousand years ago. He sensed that the mysterious black-robed figure behind the scenes was the true architect of this era. Perhaps the Hydra's true ultimate loyalty lay elsewhere.
"The Shrouded Hand warband has arrived," Kuber Hafer, Headhunter Prime of the Serpent's Teeth, announced to the Primarch. "They are primarily veterans, highly experienced in xenos-purging."
Omegon nodded. A small contingent of warriors entered. They wore ancient marks of power armor and moved with a calm, practiced confidence. However, their skin had become translucent due to the warp-taint of Chaos, revealing the raw, red hues of the musculature beneath.
As a warband that openly embraced the Ruinous Powers, the Puppet Masters immediately prostrated themselves, begging for their Gene-father's forgiveness. Their leader, Jarvul Glaine, pressed his forehead to the cold floor.
"Father, I... we welcome your return!" Jarvul cried, his heart gripped by the desperate fear that his father would execute his battle-brothers for their mutations.
Omegon merely cast a cold, indifferent gaze over them. "Stand by with the others," he said simply. Their hearts hammered with unease, but they retreated to join the growing ranks of the muster.
Over the next three Terran months, hundreds of warbands arrived: the First Strike, the Penitent Sons, the Unsung, the Guns of Freedom, the Faceless, the Sons of Venom, the Rustbloods, and many more. The Legion, severed for ten thousand years, was regenerating like the Hydra of myth—its heads regrowing, its body swelling to the scale of a true Legion once more.
Finally, a week passed without a new arrival. Drazus leaned in and spoke to the Primarch: "The warriors from Segmentum Ultima, Segmentum Tempestus, and even Segmentum Solar have largely arrived, Father. You may begin the address. Let the Legion be revealed to the world once again!"
"Very well." Omegon stood. It was the first time he had risen in weeks, his silence remaining as heavy as his armor.
Within the vast amphitheater of the Unseen Fortress, thousands of Alpha Legion Astartes stood in perfect, silent formation. Among them were the five hundred warriors of the Effrit Stealth Squad and a century of Lernaean Terminators clad in massive Cataphractii plate.
At the very front, a lone sniper stood, given a wide berth by the others out of a respect bordering on fear. This was the legendary marksman, Exodus.
Looking upon his reunited sons, Omegon spoke:
"Sons of my blood, ten millennia ago I departed from you. Today, I return bearing the will of the True God. By His power, I declare the reformation of the Alpha Legion. Follow me, follow the Lord of Murder. The decaying Imperium and its Corpse-Emperor shall fall! We shall usher in a new future for humanity!"
With a sweep of Omegon's hand, a massive, ancient, and ornate altar of anointing appeared before the Legion's Hydra icon. Upon it, a glowing green inverted triangle shimmered with malevolent light.
"Those who would follow me, bow your heads to the True God and pray! For the Lord of Murder is the Darkness of the End. He shall grant us new strength, that we may no longer be shackled by the False Emperor!" Omegon roared. Simultaneously, thirteen candles ignited, flickering with sickly, baleful green flames.
A titanic surge of warp energy began to shroud the Unseen Fortress.
Squeak... squeak... skritch...
From every corner, every shadow, and every vent, the chattering sounds of vermin erupted.
At that moment, every Alpha Legionnaire understood: their Father had returned to the galaxy through the grace of a Great Power. But to them, the source mattered little compared to the result.
The Serpent's Teeth were the first to drop to their knees. Exodus, the enigmatic assassin, followed. Then, the entire assembly of Alpha Legion Astartes knelt as one, swearing fealty to their new master alongside their Gene-father.
Countless rats began to pour out from the gloom, their grating, gnashing sounds coalescing into a multitude of tongues. As master infiltrators, the Alpha Legionnaires understood the hidden ciphers. They began to chant in unison, their voices rising in a dark litany.
"The Great Horned Rat walks among us!!"
As they completed the thirteenth recitation, a torrent of dark power flooded into the bodies of every warrior. Those capable of bearing greater "blessings" felt their legs snap and reform into digitigrade, hoofed shapes; horns erupted from brows. Most terrifyingly, their Primarch shifted, his form expanding into the towering, horrific stature of a Verminlord!
Through the thick, oily smoke of the green candles, they saw the silhouette of a massive, horned rat-skull laughing into the void.
The Warp, previously calm, began to churn violently. The western point of the Chaos Star flickered with blinding intensity, a Warp storm of a magnitude not seen since the birth of Slaanesh began to tear through the veil.
Across the galaxy, every faction felt the shockwave. In the dark city of Commorragh, the Drukhari nobility abandoned their cruel games, retreating in terror to their spires.
Yvraine, leader of the Ynnari, watched the roiling Immaterium with eyes full of complex dread. She turned to Eldrad Ulthran, her face a mask of grim foreboding. "I hope we do not live to regret allowing another God of Chaos to be born."
"The prophecies revealed that this new god would bring back the radiance of Isha," Eldrad replied. "That is all that matters. If a new Chaos God is the price for Isha's return, then let it be so. The Aeldari are already ruined; what more is there to lose?"