After all, Doomsday was created by reviving the dead. Just as Rook Tanner had been defeated by Darkseid, his army too had been crushed by Apokolips, overwhelmed by the terrifying might of Darkseid's elite forces.
At that time, Darkseid hadn't yet developed the Parademon army. The war against Krypton had been fought using only the New Gods of Apokolips.
Perhaps it was the setback of that battle that spurred Darkseid to begin researching and developing Parademon technology.
The army of one hundred thousand Kryptonian super-soldiers, each one like a Superman, had all been turned into Doomsdays. Even Darkseid had to retreat before their overwhelming might.
But this fearsome bioweapon came with a fatal flaw. Once reborn, Doomsday lost all sense of reason.
Apokolips had retreated, but the Doomsday army marched on relentlessly. Their bodies never tired. Their stamina was limitless.
And now, their red eyes turned toward the one place they were once sworn to protect with their lives.
Krypton.
Their home. Their people. Their families.
At that critical moment, Rook Tanner stepped forward and stood alone in front of the horde.
The final war began.
One against one hundred thousand.
Rook fought alone against the very soldiers who had once served under him. It was a nightmare made real, the most brutal and tragic battle of his life.
He died again and again.
But he kept rising, pushing his already unkillable body to its limits. For the sake of his home, he unleashed everything he had.
This battle was even more devastating than the war against Apokolips. The scale of carnage was too horrifying to even speak of.
But in the end, Rook prevailed.
The entire army of Doomsdays was annihilated, this time permanently.
He personally incinerated every last cell of every corpse using his heat vision, ensuring that none of the monsters could ever regenerate or be revived again.
Only after confirming complete eradication did Rook turn to look toward Krypton.
There was no cheering. No praise.
Only countless fearful, horrified eyes staring back at him.
That was when he understood.
They didn't believe he had retained his mind. They thought he had gone mad too.
Rook let out a bitter chuckle.
Without another word, he turned and left Krypton, drifting silently into the depths of space.
Before disappearing, though, he left behind one final warning:
"Do not attempt to recreate or study Doomsday ever again. Or Krypton will face its own doomsday."
It was then that the name "Doomsday" was truly born.
The being that could bring death to all civilizations. The end of days incarnate.
Following his departure, Krypton took his words seriously. All research related to Doomsday was sealed and forbidden. Even mentioning the name became taboo.
More than that, Krypton immediately abandoned its expansionist ambitions and turned inward.
A new path began.
They created the Codex of Life, a system designed to use advanced genetic engineering to produce future generations according to the needs of society.
If the planet needed warriors, it would engineer children with ideal traits for combat.
If it needed scientists, it would create minds destined for research.
Efficient. Progressive.
But also limiting.
The moment Kryptonians were taught, generation after generation, that their only purpose was to protect Krypton, they lost the will and the right to explore beyond it.
The only thing that awaited them now was extinction.
But by then, none of it had anything to do with Rook Tanner.
After leaving Krypton, he crossed the universe once more and returned to the solar system.
But he didn't head for his old base.
Instead, he dove directly into the surface of the Sun.
And then into the core.
And there, he slept.
Even with his so-called infinite stamina, he was exhausted. Not just physically, but mentally. If he didn't rest soon, even his mind might collapse.
So he slept.
Deep in the heart of the Sun, Rook Tanner slept in complete silence.
He remained there for one hundred thousand years.
A hundred thousand years.
Even in the vast timeline of the universe, that was no small thing.
But to Rook?
It passed like a blink.
He was now an immortal Doomsday, and his body, buried in the core of the Sun, continued to absorb energy, growing stronger with every passing second.
His physical strength, his abilities—everything was steadily evolving.
By the time one hundred thousand years had passed, enough to turn oceans into deserts and mountains into sea, the entire galaxy had changed.
Krypton had changed beyond recognition.
In fact, it was approaching its own doomsday.
And at that very moment, in the blazing heart of the Sun, Rook Tanner finally stirred.
His eyes opened slowly.
He had been asleep so long that a crust had formed over his eyelids, hardened like fossilized stone.
As his golden eyes opened, two blazing beams shot out like lasers.
Heat vision.
A power granted to all Kryptonians who became Supermen.
But something was different.
His beams weren't red. They were gold.
Rook frowned.
"They used to be red," he muttered.
Then he sat up, glancing down at his own body.
And understood.
His entire body was now golden. Gleaming like molten metal.
Like a living statue of light.
And deep in his mind, something shifted.
He knew things. He felt things.
He had been in the Sun for far too long, absorbing too much energy. His very being had evolved.
He had broken through the boundaries of the known.
He had become a fifth-dimensional being.
And beyond that, he could sense the possibility of reaching the sixth dimension.
The higher the dimension, the more terrifying the power.
Fifth-dimensional beings could bend reality at will, reshape time and space, rewrite history itself with a thought.
Sixth-dimensional entities were near-omnipotent, capable of creating or erasing entire universes.
And now, Rook Tanner stood at that threshold.
Just like Golden Superman from DC One Million, who emerged from the Sun after eighty-five thousand years, having become a fifth-dimensional being who could even resurrect Lois Lane and bring her into the fifth dimension with him.
But Rook had been there for one hundred thousand years.
He had surpassed even that legend.
"My god, that nap felt amazing," he laughed heartily as he leapt to his feet.
And that single movement shook the entire Sun.
Solar winds howled across space. Massive eruptions of molten plasma burst outward, unleashing a cascade of cosmic phenomena.
Rook clicked his tongue in disbelief.
"I almost shattered the Sun."
He realized he'd have to be careful from now on. His strength was beyond reason.
But even as he thought that, he looked toward the edge of the solar system, eyes narrowing.
"It's time, Darkseid," he whispered. "You and I... we still have a score to settle."
But just as he was about to shoot into space, his head snapped toward Earth.
Something caught his attention.
With his super-hearing, equal to or even stronger than Superman's, he picked up a name.
A human name.
Tony Stark.
"What the hell?"
His expression twisted in surprise.
"Don't tell me… this isn't the DC Universe?"
"I ended up in Marvel?!"
Then he paused.
"But wait… this world doesn't have Kryptonite, right?"
A slow, confident grin spread across his face.
"Doesn't that mean…"
"I'm invincible now?"
Technically, Kryptonite shouldn't have affected him anymore anyway.
But in a world without it?
He was unstoppable.