Frix felt a heat rising in his eyes, forcing himself to keep his expression under control.
He thought of the brothers who had died on Incaladion—those who had charged ahead and fallen at his side, those figures who had still been advancing in their final moments. Some of them hadn't even had their names recorded.
The lights of the training ground seemed dim beneath the shadow of the Titans. 22 war machines stood silently, their outlines like mountain ranges pressing down on the hearts of every Iron Warrior present.
Frix had seen Titans before. On Incaladion, the vast majority of their ground losses had been caused by them. It was only later, when the Mechanicum forces aligned with the Imperium deployed their own god-machines, that the situation had been stabilized.
He had personally witnessed a Titan crush defensive lines—seen a single shot from a volcano cannon flatten an entire ridge and its battle line.
But compared to the Titans before him… those now seemed like children's toys.
These Titans were more streamlined, lacking the clunky, patchwork appearance of others. Their armor plating fit together seamlessly, every joint revealing precise engineering—as if they had not been constructed, but grown as a single entity.
Each one was a mobile fortress—a war engine capable of destroying an entire city on its own.
22 of them appearing on the battlefield at once…
Frix's breathing halted for a moment.
"Father."
Berossus's voice pulled him back from his thoughts.
Standing beside him, the usually taciturn captain wore a look of unmistakable shock for the first time, his head tilted upward as he stared at those colossal machines.
"These… these will all belong to our Legion?"
Even now, he could hardly believe it.
"Yes."
Perturabo's tone was calm—as if 22 Emperor-class Titans were nothing worth mentioning.
"This is only the beginning. In the future, I will establish full production lines across the territories beyond Olympia, providing you with the finest equipment, weapons, vehicles, and fleets."
"When you next take to the battlefield, you will have my most powerful fire support behind you."
As he spoke, his gaze swept over their battered power armor and crude weaponry.
"I will no longer allow you to hurl your flesh against enemy lines, to face heavy artillery with inferior equipment. I will not allow you to suffer devastating losses, only to be treated as expendables—as 'penal labor,' as 'corpse grinders.'"
His voice echoed across the training ground.
"What you will have… will be the most powerful logistics and firepower support in the entire Imperium."
Ten thousand Astartes stood in silence.
But this silence was no longer one of unease—it was something suppressed, something on the verge of eruption.
Frix felt his eyes sting.
He lowered his head slightly, unwilling to let his emotions be seen by his father or his brothers.
Perturabo looked upon his sons, a complicated feeling rising within him.
He knew the history of his original self—knew what the Iron Warriors had endured under him. It had been a path of distortion, of stubborn, self-imposed madness.
The original Perturabo had trained them with cruelty, demanded perfection with harshness, and treated them with cold indifference.
He had not wanted to be that way—but obsession and rigidity had consumed him, and the Fourth Legion's stubborn traditionalism had only deepened his frustration.
That would not happen again.
Perturabo swore to himself that he would forge the Fourth Legion into true Iron Warriors—iron within and without.
A truly powerful army was not built on fear and oppression, but on trust and respect.
Discipline was still necessary. Training would still be brutal. Standards would remain uncompromising.
But he would make them understand why they endured these trials. He would show them what their sacrifices were for. He would make them feel that their suffering had meaning.
Perturabo turned and walked toward the Titans.
"Iron must be forged. Will must be tempered. I will shape you into true Iron Warriors."
"This is only the first step. These Titans and weapons are yours. The fleets I have built over the years will be delivered to you shortly as well."
He stopped beneath the foremost Titan.
It was the largest of them all—one hundred 52 meters tall. It was the first Emperor-class Titan Perturabo had ever designed, refined through countless iterations until its unveiling today.
The Titan seemed to sense something. It lowered its head slightly… then sank to one knee.
All of these Titans were controlled by logic engines. This one, in particular, had always received Perturabo's earliest system upgrades. In its current state, it could oversee the operations of an entire star system while simultaneously managing battlefield logistics and command.
"These Titans have no names," Perturabo said. "I created them—but I will not lead them across the galaxy."
"I believe the right to name them belongs only to those who will one day command them."
"Frix."
The First Company captain stiffened, then stepped forward quickly and dropped to one knee.
"From today onward, you will continue as Legion commander. In my absence, you will oversee the Legion's operations and command in battle."
"But remember this—I do not need machines that only obey orders. I need commanders who can think independently, adapt to changing situations, and make the right decisions in the harshest conditions."
Frix raised his head, his eyes filled with unease and uncertainty.
"Father, I… I fear that I… may not be able to—"
"What are you afraid of?"
Perturabo's voice sharpened.
"Afraid that you are unworthy? That you are incapable? Or that your inadequacy will disappoint me—and your brothers?"
Frix fell silent. So did the rest of the Legion.
"Do you know why I chose you, Frix?"
Perturabo stepped closer. The towering Astartes seemed almost like a child before the Primarch.
Frix lowered his head even further.
"I do not know, Father."
"Because I trust you."
"At Incaladion, when the 8th Expeditionary Fleet was nearly annihilated, you led the survivors out of the ruins—and continued to fight."
"You faced enemies several times your number, relentless artillery, and utter despair. Yet you did not retreat. You did not surrender."
"That is why I chose you—not your rank, not your record, but your will."
"The Iron Warriors need intelligent commanders—but we also need warriors who can stand tall even in the worst conditions."
After a moment of silence, Frix lifted his head, determination burning in his eyes.
"I understand, Father. I will not fail your trust."
Perturabo nodded, then turned his gaze to Berossus.
"Berossus."
The usually silent Second Company captain paused in surprise, then stepped forward and knelt beside Frix.
"Father."
"I know you are not a man of many words, but I have heard of your tactical ability. I need you to study every battle, analyze every engagement, extract lessons, and refine the Legion's tactical doctrine."
Berossus opened his mouth as if to speak, but in the end only nodded firmly.
"Yes, Father."
Perturabo continued calling names.
One captain after another stepped forward, kneeling to receive their new roles—some appointed as quartermasters overseeing logistics, some as instructors responsible for training, others as intelligence officers, engineers, and siege specialists.
Ten thousand warriors watched in silence as their captains stepped forward one by one to receive their father's command.
They knew that from this day onward—everything would change.
When the last captain had received his assignment, Perturabo spoke again.
"From today, logic engines will be integrated into the Legion's training. Whether in your daily routines, your lives, or future campaigns in the Great Crusade, they will play a critical role."
"This is the second step. Not only logic engines—mechanical units and Iron Rings will also be incorporated. The AI-controlled Dreadnoughts as well. You must overcome your psychological resistance—they will be indispensable in the wars to come."
Perturabo knew some would never accept abominable intelligences. The Imperial Truth had been deeply ingrained in them.
But the power of AI was undeniable. Properly utilized, it would drastically increase the efficiency of the Great Crusade—and reduce casualties to a minimum.
"From this moment on, you will undergo three months of training."
"During this time, you will learn new tactics, new equipment, new doctrines—and integrate them with your existing methods."
"The training will be brutal. My standards are extremely strict."
His gaze swept across every warrior.
"You must endure. Only then can you become true Iron Warriors."
After a moment of silence, the ten thousand warriors knelt once more.
Perturabo nodded.
"Rise. For these three months, I will train alongside you. When you return to the Great Crusade, I will monitor your campaigns through the logic engines."
"But now—the Iron Warriors must expand. I will select suitable candidates from the academies of the Olympia system for gene augmentation."
"The Legion's structure will be reorganized into Grand Cohorts. Each cohort will consist of ten thousand warriors, divided into five great companies, with independent allocation of Terminators, armor, vehicles, and firepower. Additional companies may be formed if necessary."
"Each cohort will be commanded by a Warsmith—drawn from your current captains."
"The Fourth Legion is currently undermanned. I will accelerate the gene-augmentation process to replenish our numbers."
"I have studied the Imperium's nineteen gene-seed implantation procedures. Based on my years of research with the Iron Guard, I have added three additional procedures to the Astartes transformation."
"You will undergo three days of augmentation before returning to training."
The Iron Warriors were stunned.
What did he mean—adding three more procedures on top of the existing ones? Completing them in just three days?
Just how many capabilities had their father kept hidden from the Imperium?
Mechanical units began appearing among the ranks.
"They will guide you through the augmentation process. Once complete, training will begin immediately."
Perturabo turned to leave—but then paused.
"Oh, one more thing."
His gaze swept across the warriors, carrying a deeper meaning.
"You have likely noticed the attitude of the Emperor and the other Primarchs toward me. This may lead to conflicts with other Legions during the Great Crusade."
"If that happens, remember—you are soldiers of the Imperium, protectors of humanity. Your duty is to safeguard mankind—not to compete for honor."
"Our role is to be humanity's strongest bulwark. We are destined to remain the silent Iron Warriors—without recognition, without rest."
"But remember this: no matter what happens, I will stand behind you."
"We may never have a day in the spotlight—but that does not mean we must accept injustice."
"Against enemies, I will give you the greatest weapons. Against injustice—I will be your strongest shield."
"This is my promise—as your gene-father."
With that, he turned and strode out of the training ground, Stephanie and Andos following behind.
Ten thousand warriors stood silently, watching his figure disappear beyond the gates.
No one spoke. No one moved.
They stood like statues of iron.
Frix looked at the 22 Titans… at the mountains of finely crafted armor and weapons… at the steel war machines rising from the earth… at the Achilles-pattern Dreadnoughts.
A feeling surged within him—one he had never experienced before.
It was not pride. Not excitement. Not exhilaration.
It was something deeper.
He turned to face the warriors behind him.
"Brothers."
His voice was not loud, yet every word carried across the Legion.
"Father has given us new hope. We cannot simply accept it—we must prove ourselves worthy of his trust."
"In the name of the Iron Warriors, we will return to the galaxy. And when we do, we will show all that the Fourth Legion is no longer a 'Penal Legion,' no longer 'corpse grinders'—but true Iron Warriors."
"With the blood of our enemies, we will wash away past humiliation. With the glory of victory, we will prove our worth. With iron will, we will protect humanity's future."
"This is our oath."
The Astartes of the Fourth Legion raised their right fists to their breastplates.
"Iron begets strength! Strength begets honor! Honor begets faith! Faith begets iron!"
"We are the Iron Warriors! Iron within and without!"
…
An Iron Ring approached Frix. A synthesized electronic voice emerged from its speaker.
"Sir, it is time to undergo augmentation."
Its intelligence was limited, but the presence of abominable intelligence still made Frix instinctively uneasy.
He nodded, ordering the Legion to follow the Iron Rings to begin their procedures.
No matter what—if their father had created these things, then he must have absolute confidence in them. The Fourth Legion's obedience to their gene-father was so absolute it bordered on terrifying—even to other Legions and Primarchs.
…
The surgical chamber was cold and blindingly bright.
Frix lay naked upon a tilted operating table, mechanical arms hovering above his body.
This was not his first gene-modification procedure.
90 years ago, he had lain on a far cruder operating table, undergoing the nineteen gene-seed surgeries that transformed a mortal into an Astartes. The pain had nearly torn his mind apart—but he had endured.
Step by step, he had risen—from squad leader, to company captain, to now, unexpectedly, Legion commander.
And now—
He would undergo yet another transformation, one that would elevate him even further beyond humanity.
The doors of the operating chamber slid open, and an Abominable Intelligence entered his field of vision—a cylindrical mechanical construct hovering above the ground, its central optical lens fixed squarely on him.
"Lord Frix, the augmentation procedure is about to begin. By the command of Lord Perturabo, you will be the first warrior of the Fourth Legion to undergo the three newly added procedures."
The synthesized electronic voice was calm, utterly devoid of emotion.
Frix said nothing, only giving a slight nod.
"The three new procedures will be carried out sequentially."
"The first procedure is designated the Hymnal Gland. It will be implanted near your pituitary gland, promoting extraordinary development of bone and muscle. According to Lord Perturabo's calculations, upon completion, your height will increase from 2.5 meters to approximately 3 meters, and your strength and endurance will improve by over seventy percent."
Frix's eyelid twitched.
As a veteran who had carved his way through countless battlefields, he understood all too well what such an enhancement of physical capability meant.
He would be able to wield, with one hand, heavy weapons that once required both. He could charge forward clad in even heavier armor, and in close combat, he would hold overwhelming superiority.
"The second procedure is designated the Furnace. It will be implanted within your thoracic cavity, between the heart and lungs. This is a biochemical reactor organ. When you are gravely wounded or near death, it will activate automatically, releasing large quantities of hormones and energy, greatly enhancing your combat capabilities for a short period. According to Lord Perturabo, this state is similar to a 'final surge before death,' but with greater control, longer duration, and a higher probability of survival on the battlefield."
A last resort at death's door. Frix instinctively thought of the brothers who had fallen beside him on the battlefield.
If they had possessed such an organ, perhaps in their final moments they could have slain a few more enemies, easing the burden on the battle line. They might have died with fewer regrets.
And perhaps—just perhaps—they could have held on long enough for their brothers to reach them, greatly increasing their chances of survival… though on the battlefield, such chances were always slim.
"The third procedure is designated the Tendon Coils. They will be implanted into your primary tendons and joints, providing explosive power output. These coils are composed of specialized biochemical fibers and can interface directly with your nervous system. When required, they will instantly release stored energy, allowing you to utilize heavy weaponry with far greater efficiency."
Three procedures.
Frix drew a deep breath, feeling the cold surface of the operating table beneath him.
"The procedure will last seventy-two hours. Throughout, you will remain conscious. This is Lord Perturabo's directive. All must experience each stage of the process—must feel every moment of their bodies being reforged."
Frix closed his eyes.
He remembered his first augmentation—how the apothecaries had flooded his system with sedatives and analgesics, leaving him in a half-conscious haze as he endured nineteen procedures.
Even so, the bone-deep agony had etched itself into his memory. Each procedure required time to adapt, and by the time all augmentations were complete, years had passed.
Now, he would endure three new procedures—fully conscious—for seventy-two hours.
"Begin."
His voice was steady.
He saw the Abominable Intelligence's optical lens flicker. Then the circling mechanical arms moved into position, peeling away the black carapace.
His body was opened directly—muscles across his entire frame split apart. The agony of disembowelment and flaying forced his brow to tighten.
At this moment, even an Astartes' superhuman tolerance was meaningless. Only his indomitable will kept him from breaking under the tearing pain.
Then his skull was opened.
Frix could clearly feel the blade slicing through bone as easily as cutting nutrient paste.
A needle pierced the back of his neck, reaching toward the pituitary region. A cold, stabbing sensation followed—then the slow intrusion of something foreign.
It was not pain, but invasion—a violation, as if his very being was being forcibly rewritten.
But he was weak.
"The Hymnal Gland is being implanted."
The AI's voice remained cold.
"Estimated time: six hours. During this period, you may experience severe headaches and skeletal pain. This is a normal response."
Frix could no longer hear clearly.
Pain spread from his head, then into his bones—beginning at the spine, burning outward like fire along every rib and limb.
Every bone felt as if it were aflame, torn apart and reforged by some unseen force. He could hear them creaking. Muscle fibers split and regrew again and again, becoming stronger each time.
His fingers dug deep into the metal surface of the operating table, leaving ten deep gouges.
But his eyes remained open—fixed on the blinding surgical light above.
No one knew whether he had been pushed beyond thought… or if he was seeing the flickering visions of a dying mind.
Six hours later, the gland implantation was complete.
There was no time to adapt.
The mechanical arms shifted immediately to his chest.
The second procedure—the Furnace.
This time, the pain was worse.
Two beating hearts and three expanding lungs, slick with blood, grew even larger.
He felt every incision, every gust of cold air touching his exposed organs, every moment as the alien organ was placed inside him.
He nearly lost consciousness—but did not.
Clenching his teeth, he stared at the surgical light, the blades, the syringes, the cold lens watching him.
Time lost meaning.
Seconds crawled.
"The second procedure is complete. Tendon Coil implantation will begin shortly."
Frix's eyes were bloodshot. His endurance was nearing its limit.
The mechanical arms targeted his joints—knees, elbows, shoulders, ankles, wrists. Each was cut open again. Each major tendon threaded with coiling biochemical fibers.
He felt them wrap around his tendons like serpents, linking into his nervous system, becoming part of him.
The pain had reached its peak.
He did not scream.
He no longer had the strength.
His consciousness faded—fragile as a dying breath.
This time, he truly saw the visions.
He saw brothers falling beside him in the charge at Incaladion.
He saw those sent forward by Lord Horus, blown apart by artillery—their flesh mingled with that of mortal auxiliaries, indistinguishable.
He saw his father standing before that strange Imperator-class Titan, reappointing him as commander of the Fourth Legion.
…
Frix lost consciousness.
But he lived.
Since Perturabo dared to complete the procedures in three days, he could ensure their survival. At least before the Furnace activated, none of his sons would be allowed to die on the operating table.
The augmentations were overseen by medical automatons personally designed by Perturabo. Ten thousand Astartes underwent the Primaris transformation in succession.
Frix and Berossus endured the longest. Most others fainted shortly after the Furnace implantation; a few collapsed during or just after the tendon coils were installed.
The logic engine provided real-time reports, allowing Perturabo to monitor every son.
The procedure carried immense risk. Though he had absolute confidence in their survival, the bond encoded deep within his genes compelled him to watch over each one personally.
For three days, he did not leave the augmentation chamber.
The logic engine displayed every fluctuation—organ activity, hormone levels—even as they lay unconscious.
Medical automatons administered drugs to those in danger, ensuring survival—but only survival. The Furnace had to activate naturally within them, or it would not function properly in future battles.
The activation required at least 48 hours.
One day for surgery.
Two days waiting for ignition.
Frix was the first to awaken.
The same blinding surgical light greeted him, along with the cold optical lens and gleaming mechanical arms.
He sat up, feeling the changes in his body.
His perspective was higher. The table seemed smaller. The ceiling closer.
Looking at his hands, he saw they were larger—thicker fingers, broader palms. Beneath the skin, stronger bones and denser muscles.
He stood.
His height had indeed increased—from 2.5 meters to nearly 3.
His proportions were unchanged—but everything was greater. Stronger. More perfect.
He clenched his fist, feeling power surge through him like never before.
From his chest, a force radiated outward—the Furnace had activated, pulling him back from unconsciousness.
He stood in the center of the chamber, staring at the mechanical arms, the iron ring, the unfamiliar-yet-familiar reflection in the mirror.
"Procedure successful."
The cold voice spoke again.
"You are the first warrior of the Fourth Legion to complete all three procedures. Lord Perturabo has been observing your progress."
Frix nodded.
"My brothers?"
"You are the first to awaken. The Furnace will activate within forty-eight hours. They will follow soon."
He moved to leave—but a medical automaton stopped him.
"Lord, you must undergo reimplantation of the black carapace and the armor induction ritual. Lord Perturabo has made arrangements."
"The black carapace?"
Frix glanced at his now enlarged body. Could it still be implanted?
"A custom-fitted carapace has been prepared over the past three days. There will be no rejection."
After the flawless implantation, the black carapace felt no different from his own skin.
The finely crafted power armor—fully automated in assembly—was fitted onto him in less than thirty seconds, like a product on a production line.
For a moment, an unpleasant thought surfaced—like he was nothing more than a mass-produced commodity.
But the perfection of the armor dispelled it.
…
On the training field, Frix looked upon his brothers—each no less than 2.6 meters tall, clad in masterwork power armor, better equipped even than the Dark Angels or the Luna Wolves.
A surge of pride rose within him, though his expression remained unchanged.
No one spoke.
Yet the silence carried something deeper than words—fiercer, hotter, stronger.
Frix raised his right hand, clenched it into a fist, and placed it against his chest.
"From iron comes strength, from strength comes honor, from honor comes faith, from faith comes iron!"
"We are the Iron Warriors. iron within and without!"