If one were to talk about the technological peak of the material universe, then the Old Ones were undoubtedly its ultimate summit. They mastered both matter and spirit, possessed unmatched talent, and—most remarkable of all—held compassionate hearts that pitied the suffering of all beings.
But now the Old Ones were extinct.
The Necrons slumbered in their tombs.
The Aeldari had effectively destroyed themselves with their own excess.
And humanity's Golden Age of Technology had been abruptly cut short when a rebellion inexplicably erupted and severed its development midway.
Now everyone was barely hanging on.
Sure, the Emperor leading the Great Crusade looked impressive enough—but if the Necrons ever fully awakened, their brutally materialist iron fist would smash straight into humanity's face.
So Perturabo's thinking was simple:
Then I'll just push technology further.
If he couldn't yet produce enhanced warriors like the Astartes, then he would focus elsewhere—for example, large-scale weapons of mass destruction.
They were still short on polonium and certain rare isotopes, but that didn't stop Perturabo from building some truly massive weapons.
Grand cannons.
Volcano cannons.
Lance batteries.
Macro-cannon arrays.
All of these he had already recreated using the knowledge the Emperor had implanted in him during his creation.
He had also developed large military vehicles—Stormbirds, Thunderhawks, and heavy main battle tanks. These had already been manufactured and widely issued to Olympia's military forces.
Back when he first completely absorbed the memories the Emperor had forcibly implanted into him, Perturabo had been deeply confused.
When he crawled out of the gestation chamber, it took less than three days for his body to grow to the size of a young boy.
But how could the fragile soul of someone who had just transmigrated possibly contend with the mind of a demi-god?
So the Primarch was still the Primarch.
But his mind now contained memories that did not belong to him—and habits that felt deeply ingrained.
His instincts resisted them.
Yet even then he was far too precocious, and staring directly into the Great Warp Storm above Olympia had already left his mind somewhat unstable.
After all, he was still just a child.
Conflicting memories combined with the psychic interference of the Warp—yet he still managed to suppress the violent emotions within him.
That alone was remarkable.
The moment that truly caused him to accept those memories—and completely reshape his inner self—came when he was just one year old.
It involved a shepherd he once saved.
The man looked honest enough.
One of his sheep had been taken by a predator roaming Olympia's wilderness.
He looked pitiful—Perturabo could clearly feel his sorrow and helpless despair.
So he helped.
Using the extraordinary strength of a Primarch, he hunted down the beast, killed it, and returned the sheep.
But that was the moment Perturabo truly became confused.
Because the shepherd blamed him.
Why hadn't he helped sooner?
If he had the power, then he should hunt down all the beasts for him—better yet, wipe them all out so the shepherd would never need to worry about his flock again.
The man's change in attitude was so sudden.
For the first time in his life, Perturabo's sense of values was twisted.
He didn't know whether what he had done was right or wrong.
No one had taught him.
And there were no examples around him that could tell him whether something was correct or incorrect, proper or improper.
Being born knowing allowed Perturabo to easily perceive people's weaknesses and intentions. He could often strike directly at the essence of a matter.
But that same precocious intellect made him slow to grasp emotional and ethical boundaries.
And in that moment of confusion—
The chaotic memories that had always existed in his mind finally settled into place.
They were memories from another world and another time.
Perturabo was stunned by the version of himself he saw within them.
That fragile soul gradually merged with him.
---
Meanwhile, the shepherd—standing atop what he believed to be the moral high ground—continued lecturing the child who had just saved him.
When his scolding failed to have the desired effect, he grew irritated and tried again, completely unaware of the terrifying power of the being before him.
When a kind person encounters scoundrels, things often become troublesome.
Because those scoundrels know how to grasp the naive moral instincts buried deep in someone's heart.
But Perturabo was no longer that naive.
After accepting those memories and merging with that soul, he was no longer the same child.
His body expanded once more.
He seized the shepherd by the throat.
The man's face turned purple and red from suffocation—yet that pitiful, helpless expression returned, now mixed with fear and reverence.
Perturabo disliked people like that.
Something was wrong with Olympia.
The people here were not good.
Perturabo wanted to change that.
So he crushed the shepherd's skull.
Then he climbed toward the city-state of Lochos.
With the overwhelming strength of a Primarch and his superhuman intellect, it took him only three years to unify all of Olympia.
Many rulers' skulls were crushed along the way.
Conquest was easy for a Primarch.
The difficult part was building a new order—and stabilizing it.
That itself wasn't so difficult.
But Perturabo wanted to create something more:
An ideal state.
A nation filled with logic and rational thought.
A civilization rich in art and scholarship.
A society defined by order and morality.
A utopia that existed only in Perturabo's mind.
He wanted a nation that was prosperous, civilized, harmonious—fair and governed by law—where citizens were loyal, diligent, honest, and kind.
That was his ideal.
Originally it had been even more noble.
But Perturabo could not tolerate mistakes.
Nor could he tolerate anyone challenging his authority or commands.
That was his bottom line.
His internal "core code" rejected such things.
He liked having everything under control.
He valued efficiency.
He disliked trial-and-error.
Once he identified a clear goal, he would implement what he believed to be the fastest solution.
No one could interfere.
He disliked advice.
Even when he knew he might be wrong, he still refused to accept suggestions from others.
Only he could issue commands.
Everyone else simply had to obey and carry them out.
Only when he chose to speak would ideas or solutions be presented—not before.
This was not a good trait.
Even now, after transforming Olympia into something not far from his ideal society, he still hadn't completely changed this flaw.
Though he had improved in many other ways—and had suffered a few small setbacks because of it.
Still, being born knowing had its advantages.
The Warp storm above Olympia could no longer drive mad a Primarch who had understood his own nature and possessed a stable worldview.
The sensitive, fragile, angry, suspicious Perturabo of the past was gone.
Now he was more like Jaghatai Khan—yearning for freedom and the stars, seeking poetry and distant horizons.
Engineers and construction workers have dreams too.
Perturabo now simply wanted to do research, stabilize his ideal world, and live peacefully with his sister.
That was enough.
He disliked war.
Both the present him and the former him.
Deep down, Perturabo never loved fighting.
Nor did he enjoy constantly proving himself to Terra.
What he truly loved was solving problems.
Not romantic scientific breakthroughs.
But engineering problems—clear objectives that could be broken down step by step into the smallest solvable units until the perfect answer emerged.
For him, "slacking off" did not mean lying around doing nothing.
It meant spending his time and energy on the things he truly loved.
He loved designing.
For example, designing a fortress that was theoretically flawless.
Calculating every blind spot in its fields of fire, every millimeter of structural stress distribution, every possible invasion route.
Then locking the blueprint away in a cabinet.
He had no intention of actually building it.
Because once built, flaws would inevitably appear.
Enemies would attack it.
Bureaucrats would question its budget.
A perfect blueprint did not need to face reality.
Sometimes he even enjoyed wasting time on things that seemed meaningless.
For instance, spending several days improving the leverage angle of a pair of pliers to make them 3% more efficient.
Not because it was useful—
But because an imperfect tool was an insult to an engineer.
He might write new firmware for his power armor to reduce its startup time—even if that 0.7 seconds saved would never be noticed by anyone.
Especially since he had never even worn the massive, elegant, and deadly armor yet.
He also enjoyed mathematics and physics purely for recreation.
Not the philosophical questions of theoretical physics like "Why does the universe exist?"
But elegant problems in applied mathematics.
Optimal algorithms for ballistic calculations.
Extreme derivations in material mechanics.
Defense efficiency functions of unusual geometric forms.
He didn't need to publish them.
He didn't need to apply them.
Solving the problem itself was the reward.
And he absolutely loved it.
He also had some rather peculiar hobbies.
He possessed a strange patience for things that were broken.
For instance, he might spend hours restoring an old machine tool that was decades old, studying why its designer had placed an unintuitive gear assembly in a particular position.
It wasn't nostalgia.
It was deconstructing another engineer's thought process.
He might use different etching chemicals to produce perfectly uniform matte patterns on metal surfaces.
Or cast geometric shapes whose edges formed precisely calculated curves under bright light.
He might forge a ceremonial dagger with absolutely no practical combat value—but whose proportions were mathematically perfect.
Or cast chess pieces from rare alloys that embodied pure mathematical symmetry.
He would never admit that he was making art.
A Primarch was not supposed to waste time on such things.
But Perturabo did it anyway.
Because he liked challenging himself with things no one else could accomplish.
The problems he chose were extremely specific, unusually tricky, and completely unnecessary in the eyes of others.
Yet he enjoyed them immensely.
For example:
He might research an alloy that reduced density by 0.2% while maintaining the same strength—not for mobility, but because "the extra mass balance looked ugly."
Or spend years iterating corrosion-resistant coatings—not to extend lifespan, but because "the flaking-rate curve wasn't smooth enough," which bothered him.
He might derive a closed-form solution for maximum theoretical impact resistance with minimal material usage—only to discover modern manufacturing couldn't achieve it.
So he locked the paper away.
He might design a hinge that, even after 100,000 cycles, would show virtually zero wear.
Nobody needed such a hinge.
But he couldn't tolerate structures that merely "worked well enough."
He might also become absorbed in solving a purely mathematical problem: given the mass of a projectile and its muzzle velocity, how could one reduce the terminal trajectory's sensitivity to crosswinds to the theoretical limit? Not because he wanted to make sniping more accurate—but because "the integral form is asymmetrical," and that bothered him.
He might also write a scheduling algorithm that improved fleet logistics efficiency by another 0.5%. Perhaps Ferrus Manus might actually use such an algorithm—but Perturabo himself wouldn't. He wrote it simply because the moment he saw redundancy, he had the urge to eliminate it.
Or he might rewrite the operating system of a suit of power armor, deleting tens of thousands of lines of redundant code just to reduce response latency by 0.1 seconds, all so that the startup chime sounded smoother.
He might also tune a servo unit, correcting a return deviation of only a fraction of a degree, adjusting it until the oscilloscope displayed no waveform distortion at all. Not because accuracy standards demanded it—but because the visible jagged edges in the waveform made him uncomfortable.
These were the sorts of studies he would never admit to doing.
And yet he did them anyway.
Because all of these hobbies shared one thing in common:
They didn't need to be used.
They didn't need to be recognized.
They didn't even need to be known.
In some ways, the present-day Perturabo resembled Ferrus Manus.
The difference was that Ferrus was the type of introverted engineer who secretly enjoyed showing off—even if he rarely spoke.
Perturabo was different.
He behaved as if none of it had ever happened.
These were things only he himself knew.
Even his sister couldn't understand why he was so fascinated with such strange projects.
She knew Perturabo was actually soft-hearted.
He liked being praised.
He enjoyed it when people sincerely admired his research and his strength.
She could see it clearly.
But at the same time, Perturabo was also oddly childish.
No—not childish.
It would be more accurate to say he had a habit of contradicting people on purpose.
He liked praise—but when someone actually praised him, he showed absolutely nothing. Not even the slightest change in expression, even if inside he was practically celebrating.
Instead, he would adopt an extremely serious and demanding attitude—pushing himself to do even better, and expecting others to match his standards.
He was always like that.
If someone else wanted to do something, he would belittle it or even mock them.
But when others refused to do something difficult—when they stopped because it seemed impossible—
He would be irresistibly drawn in.
Competing eagerly, demonstrating every ounce of his ability just to complete the task.
Stephanie never truly understood this "awkward" personality of her brother.
But she accepted it as she always had—just as she had wanted to protect him from the moment their father first brought him home.
For example, right now he was tinkering with an oversized, reinforced boltgun.
This was his 56,789th creation.
This was Perturabo's everyday workshop.
It was large and spacious, filled with tools of every kind.
Everywhere were works created on a whim or from sudden inspiration.
Even though Olympia's armories were already overflowing with equipment.
Weapons and vehicles produced by the assembly lines had become so numerous that storage vaults had to be constructed six kilometers underground just to hold them.
But this wasn't military duty.
It wasn't the responsibility of a Primarch.
It wasn't even a "hobby" he could openly acknowledge.
He simply had questions that mass production lines could not answer.
His sister didn't understand technology.
So she couldn't understand these questions.
For example—
The recoil mechanism of the boltgun.
The standard design had used the same buffer spring configuration for three thousand years. Why did the force curve have to take that asymmetrical shape?
Couldn't the original designer see that the extra oscillation at the seventh millisecond would wear down the locking lugs?
Or had they noticed—but simply decided it was "good enough"?
And another example—
The field regulator of the power sword.
Why did every forge world replicate the same blueprint?
Was the circular resonance chamber layout in that design truly the optimal solution?
Or was it simply a symmetrical arrangement drawn casually by some engineer ten thousand years ago, copied blindly for four centuries afterward?
No one cared about these questions.
The Emperor didn't care.
Mars didn't care.
His brothers fought perfectly well with standard equipment.
No one thought anything needed improvement.
But Perturabo cared.
Because in his mind, these things could clearly be better.
More efficient.
Cheaper.
More durable.
More lethal.
Even during the Great Crusade, Mars had never refined such technology.
The Emperor hadn't bothered.
Ferrus Manus hadn't cared about such "small matters."
But Perturabo wanted to break convention.
He wanted to prove that these things could be changed.
Perturabo's definition of "good enough" differed from ordinary people's.
Most weapon designers prioritized reliability, economy, and adaptability.
They wanted a weapon that performed at 80 points out of 100 under ten thousand harsh conditions.
Perturabo rejected eighty.
He didn't want something that worked most of the time.
He wanted every action to have a single, inevitable, logically derived reason.
And he succeeded.
Every boltgun and power sword produced on Olympia's production lines was now superior to the Imperium's standard models from his memories.
What he was doing now was simply a small personal pastime.
He liked guns.
He had made hundreds—perhaps nearly a thousand—boltguns himself.
Every one of them was a masterpiece.
Even against a Primarch, they possessed enough destructive power to be dangerous.
---
Perturabo installed the receiver and tested the locking mechanism, cycling the action a few times with the weapon empty.
The sound was clean.
Metal striking metal with the exact tone it should have.
No excess vibration.
No slack.
Every tolerance between moving components was three to five microns—just enough to maintain an oil film, but not enough to wobble.
Satisfied, he hung the boltgun on the Boltgun Wall.
Then he walked toward another workbench.
Boltguns were tools.
Long-range, replaceable mechanical systems that could be disassembled into components.
Everything he optimized about them was simply pushing the limits within an existing category.
But what he was about to make now wasn't a tool.
It was a symbol of a Primarch.
A declaration of close combat.
The point where an engineer's precision crossed into a warrior's violence.
Perturabo had never been a pure warrior.
He was calmer than Ferrus.
More brooding than Dorn.
And far less comfortable pouring emotion into weapons than he would ever admit.
So when he forged melee weapons, it was completely different from making boltguns.
He didn't even know what he wanted to create.
Warhammers.
Greatswords.
Halberds.
Massive axes.
Huge blades.
Strange experimental weapons.
He had forged them all.
In this field, he knew he wasn't as gifted as Ferrus Manus or Fulgrim, let alone Vulkan.
His talent didn't lie there.
But he still made them.
Simply because he enjoyed it.
He liked starting from a raw billet of metal, hammering it again and again, removing impurities, forging it into shape, and carving patterns into the surface.
Perturabo had once studied a theoretical problem.
If a single-crystal blade were subjected to alternating stress at a precise frequency, lattice dislocations would begin to move in a directed pattern.
On a macroscopic level, this would manifest as self-sharpening edges.
In theory, a sword "played" at the correct frequency would repair microscopic chips in its edge with every strike, keeping the blade perpetually sharp at the crystal level.
No one had ever created such a weapon.
The resonance calculations were extremely sensitive.
Material purity, crystal orientation, even environmental temperature had to be controlled to nearly absurd precision.
It existed only as an ideal case in advanced materials science textbooks.
In Perturabo's memories, there was no record of such a weapon.
But he knew—
During the Golden Age of Technology, humanity might have created something like it.
At the height of their civilization, the Aeldari likely possessed such weapons.
And the Necrons almost certainly still did.
Perturabo succeeded.
He created such a weapon.
But he couldn't be certain whether it truly matched the theoretical self-sharpening blade.
He had no way to test it.
Testing required striking an enemy.
And he wasn't ready to give the sword to anyone.
He wasn't even ready to admit that he had finished it.
All he knew was this:
Late one night, after completing the final sharpening and wiping the blade clean with a soft cloth, he raised it beneath the workshop light.
The edge reflected a line of light—
So thin, so perfectly uniform—
That he almost thought it was an illusion.
The sword now hung in the center of the Greatsword Wall.
Plain.
Unremarkable.
Its surface dull and quiet.
Now Perturabo selected another piece of metal.
He placed it on the workbench.
Then suddenly lost the desire to forge a weapon.
"Why did you stop?" his sister asked.
"…Mm."
"What did you think of this time?"
Perturabo looked at her.
Even though he had compressed his body down to just over two meters tall, Stephanie still seemed small beside him. He still had to look down to speak with her.
"I want to make a model."
"This one?"
Stephanie removed a small metal figure from her belt—a nearly perfect one-to-one miniature of herself.
Perturabo's craftsmanship and artistic sense were undeniable.
The figurine was so lifelike that Stephanie adored it.
"Mm."
"What will you make this time? Another suit of armor? Or more little figures?"
"You."
Perturabo met her bright eyes as he answered.
"But you've already made so many models of me. I can barely store them all. Every time I go out I spend ages deciding which one to bring."
"Still not enough."
Perturabo shook his head.
In the collection room there were countless chess pieces.
But there were three pieces he had never managed to create in the way he truly imagined.
One was himself.
One was his sister.
And the last one—
Was the Emperor.
"There are already so many," Stephanie laughed, holding the miniature of herself in her hand.
She loved these little figures he made for her.
"Still not enough," Perturabo said quietly.
"When I find better materials in the future, I'll make you an even better piece."
Stephanie smiled.
"Then it's a promise."