"You are the Warmaster of the Imperium! Why on earth are you dabbling in these monstrosities?!"
Following behind Perturabo, the Emperor and his companions stared at the alien-hybrids of Space Marines frozen inside cryogenic pods deep within the Demon Forge. The entire group was utterly speechless.
"Since they surrendered to us, taking a few of them for experimental purposes is hardly unreasonable," Perturabo said nonchalantly as he walked. "Besides, who wouldn't be curious about a species that is born entirely of psyker potential?"
"I dissected a few remaining Phoenix Lords and discovered that their physical structures are an absolute match for warp energy. If isolated individually, they could even trade blows with an unawakened Primarch. What kind of technology or path of evolution do you think can achieve that?"
Perturabo spoke casually as they walked. The laboratory inside the Demon Forge was lined with dense, endless rows of cryo-stasis pods. Nearly all of them contained Eldar, baseline humans, and various mutants produced through his cloning technology.
Without exception, every subject had been implanted with gene-seed and subjected to genetic modification. Yet compared to the Imperium's standard Astartes, these procedures crossed far into the realm of absolute sacrilege.
---
"So, I got curious," Perturabo continued. "I wanted to see what these knife-ears would become if they underwent genetic modification. Naturally, I ran a few tests."
"That is hardly an excuse for you to act with such complete disregard for protocol!" the Emperor said, exasperated. "Look at what you have created—does any of this look appropriate?!"
While the Emperor and Malcador viewed the sight as pure blasphemy, and Angron felt his elder brother was far too audacious, Guilliman secretly saw tremendous promise in these experiments.
If nothing else, Perturabo had secretly produced tens of thousands of experimental subjects over the years. These were merely the ones he deemed too profane to reveal publicly, keeping them locked away in this facility.
What about the borderline experiments? How many of those existed?
Guilliman knew the Warmaster had likely conducted far more. It was clear he needed to coordinate closely with Perturabo. After all, Ultramar had been treated by Perturabo as a second Olympia for years.
Countless assets had been funneled into the Five Hundred Worlds of Ultramar. As the true Master of Ultramar, Guilliman had never personally inspected what had been covertly stored within his realm.
If Olympia was already saturated with dark technology, what had Ultramar become? What state was it in now?
Although Guilliman remained confident in his administrative hold over Ultramar, he had no real estimate of how much hardware his brother had secretly stashed across his domain.
Unless they had a thorough conversation in private, Guilliman feared the Five Hundred Worlds would effectively serve as Perturabo's secondary vault for forbidden tech.
---
"Tell me the truth," the Emperor demanded, following close behind Perturabo as the Warmaster explained the initial design purposes of these alien 'Space Marines.' "Aside from these, do you have other ongoing experiments? Tell me right now—are there more?!"
The Emperor sensed this was merely the tip of the iceberg. His unruly son had almost certainly conducted far larger, more radical tests.
"A few, but not many. Time has been limited, so running larger-scale projects remains difficult."
"So how many are there exactly?"
The Emperor refused to be brushed off. The other three turned their attention to Perturabo, eager to learn the true scope of his hidden projects.
They had thought a fertile female Space Marine was shocking enough, yet the Warmaster had taken it to another level by placing alien hybrids directly on the table.
"Right here—these are the Eldar Space Marines I modified based on the Aspect Warrior paths. I reconstructed their physical frames using wraithbone modeled after the Phoenix Lords' anatomy, applying surgical procedures similar to our Astartes modifications to give them this physique."
"I tested their combat capabilities. On average, they outperform our standard Astartes, though not by an insurmountable margin. However, their psychic potential is exceptional—every single subject rose by at least one psychic grade post-surgery."
"They function as a specialized force, more balanced than standard Space Marines. But compared to elite units, the Grey Knights, or the Custodes, they fall short. Furthermore, attempting to field them systematically is currently premature, which is why I sealed them here."
"Once the Imperium adapts to the presence of abhumans, I will deploy them at an opportune moment, select candidates from the Eldar, and integrate them into Imperial service."
Perturabo deftly bypassed the Emperor's question, focusing instead on the practical results of his creation.
"And over here—I considered this earlier. When you originally created us, did you not intend to set distinct directions for our lineages? So I thought: what if I neutralized and combined those genetic traits?"
"So that's where they came from?" Angron asked, looking at the frozen Space Marines before them.
"They have been active for a long time—the Deathwatch is the result. I specifically assigned your elite legionnaires to serve alongside these chimeric gene-seed implants under the guise of advanced training. In reality, it was to instill your Chapter cultures into them."
"Otherwise, those killers would spend all their time hunting xenos without any personal direction. Giving them Chapter culture ensures they have individual purpose, preventing issues down the line."
Perturabo no longer hid the truth, laying out the origin of the Deathwatch directly. He had never expected to keep it secret forever; the chaotic galactic situation was the sole reason it had remained hidden this long. Otherwise, the strange composition of the Deathwatch—along with battle-brothers who felt strangely familiar to every Legion—would have prompted the Primarchs to investigate long ago.
"So the Deathwatch are essentially mutts made from our combined Primarch genes?" Angron asked bluntly.
His phrasing was unrefined. Though Macragge and Dame Euten had educated him well in morals and worldview, his time spent absorbing refined speech had been brief.
"Roughly speaking, yes," Perturabo acknowledged. "They are chimeras. In fact, the Chapter Master of the Deathwatch was created using a combination of my gene-seed and Rogal's."
"No wonder," Angron recalled. "The moment I met Honsou, he gave off Dorn's exact energy—a silent brick wall. Hardly spoke a word, completely obsessed with killing, practically identical to those fools in the Black Templars."
Angron remembered his meeting with Honsou. Aside from essential tactical commands, the man had barely spoken to anyone.
He had remained encased in heavy, modified Centurion armor, removing his helmet only once upon first meeting his Primarch, remaining fully sealed at all other times.
According to intelligence gathered by Cosorax from within the Deathwatch, the Chapter Master engaged in zero personal leisure. Dressed continuously in heavy power armor, he spent every moment either training or refining tactics against xenos and traitors.
He was an isolated individual, remarkably similar to Dorn's stoic lineage.
"He does his job well," Perturabo noted. "I asked him once if he wished to return to the Legion as a Warsmith, but he declined."
"Oh? He refused his creator and the Warmaster of the Imperium?"
"Yes. He stated he preferred remaining with the Deathwatch, noting that the hotheads there required his firm hand to control. Replacing the Chapter Master would require building authority from scratch, so I let him be."
"No wonder the Lion mentioned to me earlier that those Deathwatch battle-brothers suited his taste," the Emperor remarked, realization dawning on him. "He must have run into his own chimeric progeny."
"If the chimeric gene-seed implants make up the Deathwatch," Malcador cut in, "then what are these Astartes locked in here?"
The group paused, realizing the inconsistency. If the chimeric Marines had already been deployed into active service, what was the nature of the specimens sealed in these vaults?
"Once the chimeric gene-seed proved successful, I reasoned that I didn't need to limit myself strictly to Primarch genetic templates," Perturabo explained smoothly. "Why not design an entirely new strain of gene-seed? I used our genetic material as the foundational framework, then integrated external elements."
"What exactly did you integrate?" the Emperor and Malcador asked simultaneously, a dark memory surfacing in their minds—the lost Second and Eleventh Primarchs.
"I spliced in genetic sequences from powerful xenos encountered during the Great Crusade. Certain alien species possessed extraordinary abilities, and I saw no reason to let those traits go to waste."
"You tampered with xenos DNA?!"
"It was a controlled experiment," Perturabo replied calmly. "The results were successful—no mutations, no adverse side effects, and the subjects remain purely human in form. I can guarantee their absolute loyalty. However, knowing you would find their existence difficult to accept, I sealed them here."
Perturabo had hidden them precisely because the genetic modifications were radical.
Had Guilliman discovered that his gene-seed line had been forcefully spliced with the psychic manipulation capabilities of the Osirian xenos, he would have reacted with fury.
Similarly, had the Lion learned that Dark Angels genetic sequences were blended with traits from the Bone-Eaters, the Khrave, or worm-parasites, he would have ordered their immediate destruction.
Though these capabilities were undeniably effective, Perturabo knew these subjects could never be brought into the light—much like his private honor guard of cloned 'chimeric Primarchs' created from his brothers' genetic material.
"How extreme are these modifications for you to lock up fully successful specimens?" Guilliman asked, sensing a disturbing truth behind Perturabo's evasive gaze.
"Destroy these experimental subjects immediately," the Emperor commanded, his face cold. "And wipe all associated research data."
Had the Warmaster not slipped up earlier, the Emperor would never have guessed the sheer volume of sacrilegious experiments conducted behind his back.
"That is out of the question," Perturabo refused flatly. "I have female Space Marines here, let alone these subjects. I will not destroy them. If a critical situation arises in the future, deploying them to the front lines could yield decisive results."
Perturabo prioritized utility above all else. These successful specimens were merely produced ahead of their time, free of defects. Sooner or later, he intended to deploy them.
Having already created Eldar Space Marines, minor ethical concerns no longer factored into his calculations.
"How many more of these experiments are you hiding?" The Emperor let out a cold, frustrated laugh. "How is your mind more chaotic than mine? You specifically choose experiments that push directly against my boundaries!"
"Not many. Perhaps eight or ten major projects."
"Stop deflecting," the Emperor snapped. "There is no point in hiding it now. Show us."
Realizing concealment was no longer practical—and knowing new projects would inevitably arise as fresh ideas occurred to him—Perturabo conceded.
"Fine. Look all you want. There will be plenty more in the future regardless."
---
"What is this?! What are all of these?!"
Perturabo led the group deeper into the Demon Forge's core laboratories. Mechanical tendrils from the Undying Demon Dragon and Vashtorr occasionally extended into the workspace, assisting in running automated trials.
Indeed, nearly all these projects were maintained by these two supercomputer 'servitors.' Perturabo needed only to outline a concept, and they would generate corresponding schematics and testing parameters.
Once provided with physical data and raw materials, they delivered precise experimental outcomes directly to Perturabo. His high success rate over the years was largely attributable to their processing power.
"What is there to be shocked about?" Perturabo remarked. "They are merely bioweapons combining Ork and xenos traits, alongside repurposed Tyranid biological units. I analyzed their genetic structures and fused them with select xenos stock. It would be a waste not to utilize free bio-weaponry."
"Then explain why these Abominable Intelligences are merged with xenos forms!"
"Did you not see enough of this during the Dark Age of Technology?" Perturabo countered. "Even during the Unification Wars, those techno-barbarians were far more radical than I am. What does a minor project like this matter?"
Perturabo guided them through his ongoing research programs. Many were under continuous refinement; while functional prototypes existed, their sacrilegious nature meant he reserved them strictly for extreme contingencies.
He had held them in reserve even during the traitor invasion. Short of a full Necron awakening or a galaxy-scale Tyranid invasion, Perturabo felt no pressure to deploy them.
Only if the Imperium faced absolute extinction would these measures see the light of day.
---
"And what are these giant constructs?"
"Those are Emperor-class heavy Titans I constructed using living metal, Necron technology, wraithbone, and adamantine," Perturabo explained. "They combine high mobility, extreme firepower, and close-quarters combat capability. Since I lack C'tan shards, I harvested stars from outside known galaxies to serve as their individual power cores."
"I keep them stored here simply because they are difficult to manufacture. Over all these years, I have only produced one thousand three hundred units. They are reserved for countering Necron Canoptek Tomb Sentinels, which are far more formidable than standard Imperial Titans."
Staring at the thousand-meter-tall constructs before them, the Emperor and his companions were left speechless. Are the Necrons truly powerful enough to warrant this scale of preparation?
"And over here," Perturabo continued, pointing to another vault, "are entropy-acceleration weapons reverse-engineered from Hrud technology. Although local Hrud populations were eradicated, I secured specimens from other galaxies, preserved sample stock, and produced these armaments."
Coated in horrific fluids and oozing dark bio-tech aesthetics, the weapons appeared utterly profane even to Guilliman. Merely looking at them induced a sense of psychological revulsion.
The deeper vaults contained even more radical concepts: black hole charges capable of consuming entire sub-sectors, bio-Titans surpassing Emperor-class constructs in scale, and swarms designed to out-consume Psychneuein...
Every single project was an abomination that would drive the Adeptus Mechanicus into collective shock. Yet Perturabo had not only built them—he had brought them to fully operational status, ready for deployment at a moment's notice.
The Emperor and his inner circle were left genuinely bewildered by Perturabo's fixation. Was Olympia not comfortable enough? Had his sister not given him enough attention?
Why spend all his time on these insane creations?