Two years later, Nyx finally met his Legion — his sons.
The XI Legion, the 'Helix Dogma'. These Astartes were clad in golden power armour reminiscent of Nyx's own, though the hue was slightly lighter, somewhat less dazzling than the radiance of the Custodian Guard, yet possessed of a unique, cold lustre. Their pauldrons bore the striking emblem of a DNA helix — the perfect embodiment of the Legion's essence: biotechnology as both faith and weapon.
By the time Nyx arrived, his four‑man command squad had already, as expected, begun their 'proselytising'. Some warriors had even been successfully 'converted' and inducted as new members of the 'Universal Council'.
According to Nyx's conversation with the Emperor upon his return, the entire XI Legion numbered 25,000 Astartes. Their gene‑seed was exceptionally stable in itself, yet it was also highly susceptible to external influence or self‑directed mutation.
The Emperor had not explained the reason clearly. He had only told Nyx that he would understand naturally upon arrival. It was precisely because of this mutation that the Emperor had strictly forbidden them from further expansion.
"I sense it... That is our father!"
None knew who first cried out. In an instant, the entire Legion fell silent. The gaze of every warrior converged upon Nyx. The resonance and affinity from the depths of their blood swept through each of them like a tidal wave.
In that moment, many warriors had tears in their eyes. Without confirmation, the genetic bond was unmistakable: this was the gene‑sire they had so long awaited.
"All ranks, form up! Remove your helms — honour our Gene‑father with your true faces!"
The Astartes standing in the front rank issued the order, steadying the stirred crowd. He was evidently the son tasked with commanding in Nyx's absence.
"Report to Lord Nyx!" He stepped forward; his power armour emitted a subdued rasp. "I am Sauk Arthas, Captain of the 1st Company, Helix Dogma. I have held temporary battle command pending your return."
...Ah. Arthas?
Countless associations flashed through Nyx's mind in an instant — this name... Should he, one day, procure a few 'Frost Mournes' for himself?
Despite the turbulent complaints in his heart, he maintained the solemnity and affection befitting a Primarch. His gaze swept gently across every face, each brimming with anticipation.
"My children." His voice carried clearly through the hall. "I know you have waited long for this moment."
"I feel your loyalty. Your trust in me."
"The first moment I saw you, I knew — you are my pride."
These words brought the big Astartes men, who had already held back their tears, to the verge of weeping once more. The four captains witnessing this scene were also deeply moved.
Nyx perceived that his children possessed a vibrant — even naive — disposition. Unlike certain Legions whose feelings toward their Primarch might be complex or ambivalent, the warriors of Helix Dogma exhibited unconditional trust and dependence. This was, for him, a relief — but also a faint, heavy sense of responsibility.
The corona of faith behind Nyx's head stirred of its own accord. This scene was much like the Emperor when He first came before many of His sons. Nyx felt the sons' trust in him rapidly swell.
Hm—?
Amid the sea of joyful sentiments, Nyx sensed an undercurrent of panic and anxiety washing toward him.
His gaze slid past Arthas and fixed upon the end of the formation. A figure attempted to evade his notice — but it seemed... something else?
"Father... Father?!" Arthas followed Nyx's gaze. Instantly, cold sweat soaked his undersuit.
"Forgive me!" He dropped abruptly to his knees, his voice lowered, trembling almost imperceptibly. "It is... the 2nd Company Captain. Mordred. He has... privately conducted biological modification experiments."
The more Arthas spoke, the quieter his voice became — like a child fearing a parent's rebuke after transgressing. Within Helix Dogma, bio‑modification was not forbidden, but it was subject to strict regulation and limitation. 'Excessive modification' — such as Mordred's, which had resulted in anomalous limb growth — had undoubtedly crossed the red line.
And this was, in the acting battle‑captain's eyes, a grave dereliction of duty. Arthas did not fear punishment. He feared that his gene‑sire might be disappointed — even disgusted — by his progeny. That, to them, was more unbearable than death.
"It's alright, Arthas. I understand."
"I will never hate my children because of this. On the contrary — I simply wished to see for myself the extent of Mordred's changes."
Nyx strode forward, parting the neat, solemn ranks of Helix Dogma warriors, all the way to the end of the formation.
There, he met his sons — those whose bodies had clearly undergone mutation.
Limb hyperplasia. Exposed chitinous plates. Distorted joint structures. Strange striations spreading across their skin...
The consequences of unrestrained biotechnological transfiguration were starkly, brutally embodied in them.
Gazing upon these sons, Nyx suddenly grasped the deeper import of the Emperor's earlier warning. He also dimly understood why, in the original timeline, the XI Legion had been quietly expunged.
When biotechnology was pushed to such extremes — if the Emperor did not permit it — it would be all too easy to fall into the abyss of Chaotic corruption. Their continued existence would be tantamount to a potential catastrophe for the Imperium.
But that was the Emperor's choice. Not Nyx's.
These mutated warriors were, first and foremost, his sons. Nyx understood: this was the Emperor's test for him — to see if he could make the 'correct' decision. Whether he would, out of a soft heart, retain these 'unstable elements'.
The Emperor knew that these heavily mutated Astartes were a stain upon the Legion. Even if their Primarch personally executed them, it would not harm Nyx's prestige within the Legion — rather, it would demonstrate his resolve and discipline.
For these mutated Astartes, to be executed by the Primarch's own hand was an honour. It was the Primarch's greatest mercy.
"Father... Please... Do not look upon my tainted form any longer..."
"Let us end ourselves... Do not let our existence defile your hands."
Mordred and the other mutated warriors hung their heads. Their voices carried only endless remorse and self‑rejection. They had, of their own accord, stained the Legion's first impression in their Gene‑sire's eyes — a sin that not even death could expiate. The only thing left was to end themselves before they caused further shame.
"Calm yourselves, my children. I said — you are all my blood."
"No one has the right to decide your life or death — including yourselves — unless I grant it."
"Your sacrifice shall occur only upon the path of the Great Crusade, in the course of reclaiming the galaxy. Until then, your sole mission is to consider how you may add a cornerstone to humanity's rebirth."
"Father, I..."
Mordred was almost incoherent with shame. Nyx's tolerance and gentleness were like the brightest light, illuminating the disgrace in his heart — a disgrace with nowhere left to hide.
"Do not worry. Leave everything to your Gene‑father."
"Magnetic field rotation — 250,000 horsepower!"
"CELLULAR RECOMBINATION!"
Nyx spread his arms. A majestic golden current erupted forth, like a crown, softly yet irresistibly enveloping every mutated warrior.
In an instant —
The hyperplastic limbs crumbled and dispersed like walls of sand. The distorted joint structures were smoothed and rectified by an invisible force. The alien markings faded away. The pure, human form of the Astartes warriors was restored.
There was no pain. No laceration. Only a warm current of recuperation flowing through their veins.
When the current subsided, they lowered their heads in astonishment — beholding their own whole, coordinated bodies — and the shock and hope that blazed in the eyes of their brothers around them.
"This is MY choice!"