The dim light of Immora, the first city in creation, flickered, casting jagged shadows across its obsidian halls. The air reeked of blood and sulfur, a battlefield's lingering stench. Demonic corpses lay scattered, their flesh still smouldering from the Doom Slayer's relentless wrath.

Before the Doom Slayer, in a seemingly impossible state of tiredness, stood the Father, the being many called God, his once-immense power now reduced to a flicker. His form was gaunt, his divine radiance a pale imitation of its former glory. Beside him, the golden, shimmering Maykrs loomed—ethereal and commanding, their presence both alien and inscrutable.

"You have done what none could have foreseen. My creator is no more. You have unmade the Dark God."

The Doom Slayer stood silent. His battered green Praetor suit bore the scars of his final battle, the once-imposing armour dented and burned. His dark visor gleamed faintly in the dim light, but behind it, his eyes were hollow. The unrelenting fury that had driven him forward for so long was gone, leaving behind only emptiness.

The Maykrs' voices echoed, layered and melodic. "The war is over, Doom Slayer. You have vanquished what could not be conquered. Your purpose here is fulfilled."

He gave no answer, his silence a quiet rebellion against their proclamation. He knew they were right—the mission that had consumed him, defined him, was over. But the finality of it clawed at his soul like a blade turned inward.

The Father watched as the Maykrs descended toward the Slayer, their glowing hands outstretched. He did not resist as they guided him forward, their golden light dimming the harsh edges of his ruined armour. They led him to the sarcophagus prepared long ago, its rune-inscribed surface thrumming faintly with power.

"By your hands, all things were remade—even you," the Father spoke again, his voice heavy with resignation. "You ripped, you tore… until it was done. And now it is done."

The Slayer, silent as ever, lowered himself into the dark confines of the sarcophagus. His armour hissed as it locked into place, his form now motionless. The Maykrs hovered above, their light casting long, mournful shadows as they began sealing the tomb.

One final proclamation echoed from their radiant forms. "The Doom Slayer has fulfilled his duty. His war has ended. Now must his rest begin."

As the sarcophagus sealed shut, darkness enveloped the Slayer. The Fortress of Doom, a monolithic vessel of bloodstained history and countless weapons, became his eternal resting place. The Maykrs cast it adrift into the Argent Sea, a realm beyond the multiverse, beyond even the makings of the Dark God.

But eternity is never certain.

Across the dimensions. In another place, another universe, humanity waged its endless war. Across the vast Imperium of Man, from the lowliest trooper of the Astra Militarum to the towering genetically enhanced Space Marines, every soul fought to defend mankind. Alien horrors and traitorous heretics serving chaotic gods lurked on all sides. In the grim darkness of the 41st millennium, there was only war.

101.M41

The Deathwatch, the Emperor's elite xenos-hunting space marine force, were the first to report sightings of the Fortress. At first, it was suspected as an Xenos artefact. Then, the Mechanicus of Mars intervened, declaring it to be archaeo-tech of human origin, predating the Imperium of Man itself. Many tried sending probes to study it, but all attempts before the Fortress proved futile. It slipped between realspace and the Warp unpredictably, its arcane systems baffling even the Mechanicus' most advanced sensors.

150.M41

The Aeldari, with their heightened psychic senses, detected a presence within the alien structure. Their Farseers warned that it was ancient and slumbering, far beyond mortal comprehension. They called the being inside "Slumbering God" and urged their kind—and grudgingly, even other factions—to avoid it at all costs.

But the whispers of potential catastrophe spread unease. Some Craftworlds dared to suggest the fortress might be a weapon against Chaos, though they feared the consequences of waking whatever dwelled inside.

226.M41

A rogue trader speaks of an encounter with an Ork warband attempting to seize the Fortress. Believing it to be a treasure trove of powerful technology, the greenskins rushed to board it. They did not survive.

The Fortress obliterated the Orks the moment they drew near. No weapons were fired, and no explosions lit the void—just silence, followed by the sudden absence of life.

[ Time Irrelevant ]

Even Chaos warbands could not resist the lure of the Fortress during its stay within the Immaterium. Daemons and heretics alike sought to corrupt and claim it, lured by dark visions of power. None returned.

405.M41

The Deathwatch observed a Tyranid Hive Fleet crossing paths with the Fortress. Designated Hive Fleet Xy'athul, its bio-ships surged forward with the intent to consume everything. But as they neared the structure, they were destroyed.

The Hive Fleet vanished in an instant, obliterated by forces beyond comprehension. Void-camera recordings showed no energy signatures, no weapon fire—only the aftermath: Nothing. The Inquisition classified the event as "anomalous," and the Fortress disappeared into the Warp once again.

444.M41

In the blood-drenched Hive World of Armageddon in the Segmentum Solar, unknown to most of the Imperium, there was a titanic clash between the Forces of Chaos and the defenders of Man. A representation of the culmination of years of preparation by the former Primarch and Daemon Prince Angron, the favoured Champion of Blood God Khorne, to unify his World Eaters after the Battle of Skalathrax thousands of years ago had led the XII Legion to break up into numerous scattered warbands.

No one expected, the massive space hulk known as the Devourer of Stars, carrying a mass of chaotic space marines, heretics, various raging daemons, and daemon-possessed war machines to descend upon the part of the planet known as Armaggedon Primus, already struggling to keep functioning amidst the ever-growing riots. It was then that the Fortress of Doom emerged once more, and the Doom Slayer had finally awakened to make his debut in the wartorn galaxy.