"Child, your strength is astounding. Even the Primarchs I fashioned did not possess such power in their youth. You astonish me.
"You may not yet grasp just how powerful those Primarchs are, but believe me when I say they stand for the very pinnacle of humanity. In every respect they are unrivalled, yet in raw combat prowess, you already match, even outstrip, them. That is a rarity indeed." The Emperor crouched before Axis as he spoke.
"Thank you for the compliment," Axis replied.
'We Saiyans may lack many things,' he thought, 'but when it comes to fighting power, we sit on the very ceiling!'
Still, he knew he could not compare with the Primarchs in other ways.
The first, the Lion, Lion El'Jonson, had lived ten millennia and merely gone white-haired.
Vulkan, Lord of the Salamanders and a true Perpetual, could in theory resurrect forever so long as his soul remained intact.
Every Primarch is unrepeatable; their making drew on shards of lesser Warp gods, perfect masterpieces of the Emperor's own hand.
"That is why I intend to design a personalised programme of genetic augmentation for you," the Emperor continued. "Without damaging your existing genome, we will strengthen you in every aspect."
Axis already rivalled, indeed slightly surpassed, a Primarch child. Should he reach maturity unhampered, his future would be limitless.
After only a cursory inspection the Emperor had seen the truth: implanting a standard gene-seed and reforging him as an Astartes would stunt his potential.
His innate genetic resilience far exceeded that of ordinary Space Marines. What this boy needed was tailor-made enhancement.
The Custodes are his future.
"I hold high hopes for you," the Emperor declared. "I shall make you a Custodian. Perhaps you do not yet know what that title means. Put simply: across the Imperium, in terms of sheer physical might, only I and the Primarchs surpass the Adeptus Custodes, no one else. And every Custodian's augmentation is bespoke."
The Astartes are merely mass-produced soldiers. In his eyes, the Custodes embody the perfect human form.
By adulthood Axis' power would already rival a full-grown Primarch; with Custodes craftsmanship his strength would soar still higher.
Among the Emperor's personal guard there would arise one who could keep even a Primarch in check.
The Emperor had no intention of shaping Axis into an ordinary Custodian or even a Shield-Captain.
He would groom the boy as Valdor's successor, the next Captain-General of the Custodes.
The Emperor's gaze upon Axis blazed, as though he already saw before him the future Lord Commander of the Custodes, a warrior whose might could eclipse the Primarchs themselves.
'Damn!' Axis could scarcely believe it: the Adeptus Astartes path wasn't for him at all, his upgrades would be Custodes-grade!
In the grimness of the 41st millennium, the Adeptus Custodes sit right at the combat power ceiling.
Unlike Astartes, they don't receive a foreign gene-seed; their bodies are refined, their own genes perfected.
A Saiyan's DNA is already monstrous, enhancing it the Custodes way would push Axis's potential even higher.
And in sheer lifespan a Custodian also outlasts a Space Marine by centuries. It was a Jackpot. Custodes truly suited him.
Russ scratched his chin.
"So Custodes are much stronger than Space Marines? Then why not mass-produce them?"
"They are my most perfect masterpieces," the Emperor replied, pride flickering in his golden eyes. "The Legio Custodes, the Ten Thousand, are the single most powerful fighting force in the Imperium, bar none. But the cost of a single Custodian equals that of thousands of Astartes; fielding even ten thousand strains the Imperium's coffers to the limit. Mass production is impossible."
Every Custodian is trained from childhood.
Their personalised genetic surgery alone is extravagant; subsequent decades of tutelage, not to mention arms and armour, dwarf the expense of a Space Marine.
Take armour: an Astartes wears ceramite or adamantium-reinforced plate. A Custodian's power armour is wrought of auramite, a metal inert even at the quantum level, phenomenally resistant to psykery and all other forms of energy.
The Emperor's own war-plate is forged from the same substance.
One suit is worth a world.
"I see. So a single Custodian is obscenely expensive," Russ nodded.
He had to admit: for the little whelp beside him, Custodes augmentation was the perfect fit.
"There's simply no comparison," the Emperor went on. "Enough, go consolidate your tribe. I'll have a few transports prepared. My flagship is in high orbit above your world; once you are ready, come to me. I have also arranged a Gloriana-class battleship as your personal flagship."
The Custodes were his pride; the Astartes merely a stabilised, mass-produced echo of the ancient Thunder Warriors.
To compare the two was an insult. An Astartes could never outmatch a Custodian, every Custodian is a savant of martial strategy, able to fight alone, in concert, or command entire armies.
What the Astartes possess is scale; what the Custodes embody is not only strength, but the very legitimacy of the Imperium.
Russ, his vigour returned, hauled himself up and nodded to the Emperor. With Axis and the two wolf-brothers at his heels he made for the exit.
"Russ," Axis said softly, "even after I undergo Custodes augmentation, I'll still recognise you as my foster-father. When my training is complete, I'll come back and fight the Great Crusade at your side."
The battlefield was a Saiyan's home.
Whether Custodian or not, Axis had no intention of hiding behind the Emperor's throne on Holy Terra.