For the details, Rhodes and Guilliman coordinated, like arranging transport personnel and releasing news of an Emperor Avatar.
"Rhodes, this Emperor Avatar's base form—the Ace Killer—how is it made? This lifeform is truly marvelous," Guilliman asked.
"I used to produce them secretly, but this time I'll bring sufficient materials and make one openly in the Martian Mechanicus," Rhodes grinned.
After creating the extradimensional space with Yapool, Rhodes no longer lacked extradimensional energy. If he wished, he and Yapool could fabricate Ace Killers with raw energy.
But their mass-produced ones weren't as good as the system's. The system's could level up, get free extradimensional metals, and strengthen cores.
The ones he and Yapool made could absorb energy but couldn't be strengthened—far inferior in growth potential.
"Ace Killers are forged from extradimensional metal, plus vast extradimensional energy.
"These used to be scarce, mostly reserved for making Hyper-Beasts," Rhodes said.
Since creating the extradimensional space, Hyper-Beast upgrades have increased. Rhodes is confident he can, within years, upgrade all Custodians in the Palace into Hyper-Beasts.
As for Custodian loyalty:
Rhodes has been named Imperial Heir Apparent; to some extent, he's become the Custodians' new focus of fealty.
After Hyper-Beast conversion, at a subconscious level their loyalty to Rhodes grows daily.
And the Emperor has given Rhodes the Custodian modification protocols. With the Hyper-Beast machines they can be mass-produced, though at high energy cost.
Hence Rhodes wanted the Custodian protocols—to perform conversions in his own domain. One Custodian takes 20–30 years to complete.
With med-bays, success rates rise greatly, and Yapool, Balt, and Zett can research enhancements.
"I see. If produced within the Martian Mechanicus, Fulgrim will be more at ease," Guilliman said.
…
Days later, Rhodes brought 100,000 tons of extradimensional metal and Yapool to Mars, assembled many Tech-Priests and other Magi, even Great Magos Belisarius Cawl.
Then they loudly publicized the Ace Killer. They declared that after creation, the Emperor would infuse it with his psychic might to become an Emperor Avatar of terrifying power.
The Mechanicus had long been curious about the mysterious avatars; now, with permission to produce one, they were eager to see it.
Unlike the slow, methodical Magi, Yapool working with Rhodes, drawing enough extradimensional energy and metal, made an avatar with ease—in just half a month!
In the remaining half month, they made another. In a single month on Mars, two avatars were completed.
To make it grand, the Emperor even held a public ceremony on Holy Terra.
Before all Imperial citizens, he infused golden energy into one avatar, transforming it into an Emperor Avatar.
The people watched a red giant turn into a gold-armored giant in the Emperor's image.
All citizens cheered; they finally knew how the mysterious avatars were made.
It wasn't some Warp sorcery, nor a new living saint of the Emperor.
It was science—plus the Emperor's psychic power!
Imperial officials recorded the ceremony and broadcast it across the Imperium.
The Emperor Avatar's method was finally public—and Chaos learned it too.
…
"So that's it. They use a strange energy. No wonder—no wonder the body's strangeness kept scripture from duplicating it," Vashtorr said in the Warp.
Beside him stood Abaddon. He had completed a new round of gigantification; his strength now nearly matched a giant Primarch.
After the method was public, he immediately brought the recording to his partner, Vashtorr.
Seeing the process up close benefited Vashtorr greatly. He also realized the gigantification he'd devised differed clearly from the Avatar.
"If we can get a base-form specimen, perfect. We can try infusing other energies—mine, undivided Chaos, or the other gods'," Vashtorr said.
"I've thought the same. I even suspect that so-called Child of Slaanesh is just a mutated Ace Killer!
For some reason Slaanesh cooperated with the Emperor and obtained this lifeform," Abaddon snorted.
The puzzle that plagued him was solved: you're merely a manufactured bioweapon, not some spooky demigod!
"No, not quite. I've seen that Child of Slaanesh. It resembles these, but if you simply inject Slaanesh's power, it shouldn't be that strong," Vashtorr shook his head.
As one foot into godhood, his eye was keen. The Slaanesh-infused avatar was unlike the Emperor Avatar's base form. Too much god-power would be rejected; too little wouldn't reach that might.
He was puzzled. To understand, he needed an uninitialized specimen.
"That won't be easy. If you want an Emperor Avatar, I can probably help capture one," Abaddon mused.
To topple the false Imperium, he needs a counter to the avatars. Vashtorr's gigantification needs further upgrades.
And that tech is only for Chaos Champions, Lords, or Daemon Princes. He wants a cadre of avatars belonging to him, Abaddon.
So mastering the Avatar's manufacture is crucial.
"An Emperor Avatar is no use to me. I've recovered some of their remains on battlefields.
"Only the untouched base form will do," Vashtorr said.
"That's not easy, but I'll keep watch. If a chance comes, I'll try to grab one," Abaddon nodded.
At the same time, the other Chaos gods received the broadcast and learned the method, further convincing them Slaanesh had cooperated with the Emperor.
This lifeform that can absorb their god-power to forge special warriors is formidable. They must obtain it.
Right then, Rhodes's Slaanesh-Killer underling moved. First he revealed this to his loyal lackey, Lucius.
"My lord! Is that true?" Lucius looked in disbelief at the purple giant.
Recently, mortal Slaanesh cultists, Daemonettes and Princes found it odd—their link to their patron had been cut, then returned—but now there were two.
One stronger, one weaker!
All Slaanesh daemons were confused.
Rumor spread that the so-called Child of Slaanesh, Sidonis, was merely an Emperor Avatar.
Their former patron had allied with the Emperor; a new Slaanesh was about to rise.
"To be honest, Lucius: the one who made you Champion has abandoned her Chaos godhead and fully embraced Order. I am the product of her deal with the Emperor," the Slaanesh-Killer, under Rhodes's control, confessed partially.
Though Aisha abandoned the godhead, Lucius, being her Champion, still had some link.
"My fealty has always been to the one who made me Champion, never to any Primarch or some 'new Slaanesh.'
"If that great one embraces Order, I embrace Order.
If that great one chooses Chaos, I choose Chaos," Lucius said.
He never got on with his Primarch, and he didn't know who the new Slaanesh was. Following his current patron seemed better.
"Good, Lucius. Then now your master has a special task for you."