The Emperor felt his mind being pulled into the beacon, beckoning him to meet with the being beyond the rift. With a deep shuddering breath, the Master of Mankind took the plunge. A flash of golden light filled the Chamber and reality shifted. Malcador and Valdor both braced themselves in fear as the light swallowed there Master.
The Emperor's eyes shot open, he had delved into the beacon and wherever he was, this too was part of the message. The first thing he noticed was the smell. Incense and ozone hung in the air in an overpowering amount. The Emperor was grimly reminded of the countless Cathedrals he had visited and destroyed. The second thing was the truly obscene amount of psychic pressure in the room. His supernatural and physical senses were both muffled by the bombardment of excessive stimuli.
He scanned the chamber around him in the hazy half-light, attempting to get his bearings. The Emperor was standing at the foot of a gigantic staircase that ascended a pyramid of machinery and religious iconography. A scowl settled on the Emperor's face as he walked towards the stairs. He was obviously in some sort of temple of obscene opulence and meaning to whatever misguided fools created it. As he reached the first step he was startled by what at first he had assumed were statues standing on either side of the First step. They were Custodes, unmistakable in their Ornate armor. The Emperor recognized them as Hetaeron Guard, his nature as a psychic projection masking him from their view. He observed this counterpart to his companions. They were practically identical except for a single worrying detail, their cloaks were not the flowing red of the Custodes he knew but a ragged black raiment of grief.
Horrific realization poured over the Emperor's mind as the nature of the massive chamber he was in became evident. It was a tomb, his tomb. Wherever or whatever was the source of the Beacon it came from a place where he had fallen. Taking a deep shuddering breath the Emperor knew what must be done and began to ascend the pyramid.
Slowly but surely he climbed the artificial mountain. The psychic aura was only becoming stronger and the Emperor could feel the storm of energy buffet his mind, body, and soul. Every hundred steps there were twin platforms on either side of the stairs. A Custodes stood on each platform flanking the steps. The Emperor grimaced as he looked at these doppelgangers, every pair seemed to be more injured and damaged. The first pair he noticed with damage had small scorch marks on them, but as he ascended the damage became much more apparent. Their golden armor was blackened and twisted, no longer the ornate wargear of his closest companions, but broken slag clinging to decrepit transhumans.
Trying to shake off the growing feeling of unease that gripped him, the Emperor continued his ascent with gritted teeth. The psychic inferno raging at the top of the pyramid stung his skin and soul as he approached, the sheer amount of psychic energy pouring off whatever sat at the top of this structure could boil the blood of lesser beings and snuff out there souls like a candle in a gale. The Emperor was getting close to the top, a few hundred steps and he would reach the peak of this grotesque monument. The next pair of Custodes he saw made him stop for a second. The one on the left had impaled himself on his guardian spear, it stuck through his shoulder as a morbid crutch to keep the transhuman warrior standing upright. The one to the right had his armor had fused with the floor and its occupant seemed to be slowly burning to death inside, yet despite the clear pain and torture both men were under, neither one of them moved or made so much as a sound.
Cursing under his breath, the Emperor sped forward past the broken guardians, moving with superhuman speed up the last bit of the staircase, not stopping to look at the remaining Custodes. Every second spent in this broken reality where his companions were reduced to such a state and his tomb had become a temple grated on the Emperor's mind. Whatever this message was, it must contain answers to what created this realm.
After hours of climbing, the Emperor of Mankind reached the summit. The psychic energy that pressed upon his soul had reached a new level of intensity. Reality shimmered and seemed to burn under the mass of raw mental and spiritual power pouring forth. Gathering his energies to cloak himself, the Emperor approached the scalding psychic light. He could feel the death howl far more clearly now and a shiver ran up the Emperors spine as his psychic senses detected something new to the psychic scream. His psychic wail was part of it, the loudest and most horrific by far but not the only one, not even close. A chorus of agony and death echoed with his own. Millions, if not billions of individual psychic screams could be heard in the Warp-Born cacophony.
Finally, he was close enough to cut through the psychic and physical miasma that obscured his senses. The nature of the pyramid and its capstone became apparent. It was a hulking machine that funneled colossal amounts of energy into a throne. The Throne often seen in the Emperor's own visions. The Throne that could be humanity's salvation and the path to ascension. Slowly the Emperor approached the massive object, scalding psychic light cascaded off of the Throne obscuring the Emperor's senses as he approached. Then finally, when he stood directly before it, he could see its occupant freely. For the first time in millennia, the Master of Mankind wept.
The thing on the throne was grotesque, a rotting, broken corpse held together by sheer psychic might and technology that should have been left forgotten in ages past. Thousands of innocents were fed mind, body, and soul to the husk. This abomination stuck on the precipice of Death disgusted the Emperor, it was an undead monster filled with more psychic power than anything he had ever seen that screamed a never-ending Death Knell of despair and agony. The thing on the Throne was Him.
Fighting back the urge to wretch the transhuman champion of the human species felt an emotion once thought gone to him, fear. Something somewhere had not just killed him but distorted him into a psychic parasite that fed off of others to prolong the inevitable. This corpse on the Throne was worshiped like a god. Not just any god, but the worst kind of deity that the Emperor had spent so long trying to defeat. It was failure incarnate, the manifestation of all his worst fears and doubts. Falling to his knees, the stunned Emperor of Mankind could not help but wonder aloud.
"How?" that single word filled with distress and fear hung in the colossal chamber for a long and terrible moment. How had his dream failed so horribly? In this twisted place, he had been reduced to a corpse on the edge of life and death in some sort of macarabe temple of sacrifice.
Millions of thoughts swirled through his transhuman mind. Someone had brought him here to see this, someone powerful. It was not the Ruinous Powers, for all there power and schemes they held no purchase on him and such tricks and traps could never reach this level of intricacy. No, this was not an illusion but some other time or place. The remaining candidates for the beacons creation were equally worrying. The Dragon of Mars? One of his wayward children? A future Primarch? A surviving Elder One? Or a last desperate call from the corpse in front of him in order to prevent this future.
Before the Emperor could continue his stream of thoughts, a sudden psychic pulse reverberated through the chamber. A wave of psychic energy rolled off of the Throne like an ocean swell, crashing upon the stupefied Master of Mankind. Then a second pulse occurred, then another. It reminded the Emperor of a grossly magnified heartbeat, and it took the Emperor a split nano-second to realize that was exactly what it was. In a profane parody of resuscitation, the Throne was pouring Psychic energy into the corpse forcing its broken form to somewhat function. Slowly moving closer to his deceased counterpart, he wondered if it was possible that some parody of life still dwelled in the decayed thing in front of him?
He got his answer when the Corpse-Emperor stirred to life. Its eye-sockets suddenly glowed with supernatural light while it's attached arm slowly reached out towards him. The carcasses jaw fell open and in a voice that could shatter worlds and dominate armies, it spoke.
"Emperor Athām the Revelation: Master of Mankind, Anathema to Chaos, Augustus Imperator, Father of the Imperium, Lord of Terra and Mars, Omnissiah, Lord of Perpetuals, Sire of Heroes, and the New Man. We must speak to you"