"Doctor, do you really intend to make Suikazan Fuguki the Mizukage? Do you honestly trust him that much?"
Under the glare of the shadowless lamp, Orochimaru asked Vegapunk—who was performing the modification surgery—with a strange smile tugging at the corner of his mouth.
"Heh, how could that be?" Vegapunk replied coldly, hiding nothing from Orochimaru. "If I truly wanted to remodel him, a single shot of Gene Modification Fluid would suffice. As my assistant, have you ever seen me resort to actual surgery for modifications?"
"So, Doctor, you must have come up with something new again. Poor Suikazan Fuguki—he rushed here just to volunteer as a test subject."
Orochimaru looked as though he had expected nothing less, curiosity gleaming in his eyes.
"It's not exactly a new concept; I've long since become proficient at this procedure. Only the conditions are a bit different this time, so there may be some variations."
Even as he spoke, Vegapunk guided a scalpel to slit open Suikazan Fuguki's skull. The high-frequency vibrating blade, impossibly sharp and controlled with supreme precision, lifted off the top of Fuguki's cranium, exposing the brain beneath.
Next, Vegapunk operated directly on the brain, incising certain regions, then retrieved a peculiar piece of tissue from the instrument table and inserted it into Fuguki's head.
The tissue resembled a miniature brain, its convolutions patterned like circuit boards, pulsing with a faint, rhythmic glow—as though it were breathing.
Noticing Orochimaru's curiosity, Vegapunk explained, "That's a quantum brain interface. It links directly into the quantum brain."
Orochimaru nodded thoughtfully. Though he had never seen a quantum brain, he had heard Vegapunk describe it—the doctor's crowning achievement. At full capacity it could compute on a galactic scale, simulating every inanimate particle's motion within an entire star system.
"Via the interface I can control the subject, with six slots in total. Beyond that, the issue isn't computing power—it's my own capacity to manage them," Vegapunk said.
"This control doesn't turn the target into a puppet. It preserves every facet of personality and ability while unconditionally shifting allegiance, making them my devoted vassal."
"Heh, then I suppose I should thank you, Doctor, for not installing one of those in me."
Hearing that, Vegapunk shook his head. "Don't be naïve. Nothing in this world is flawless. Once the quantum brain interface is implanted, the subject may retain intellect and personality, but all creativity and inspiration are gone forever."
Only then did Orochimaru understand why Vegapunk hadn't tried to control him. Meanwhile, Vegapunk sighed, memories of his three former assistants surfacing once more.
Regrettably, he had discovered the flaw only after operating on them. Even after removing the interfaces and erasing their memories of that period, the three had deduced what had happened from the gap in time and vanished without a trace.
That incident, however, had planted a suspicion in Vegapunk: perhaps the wellspring of human inspiration lay not in the brain but in the deeper level of the soul. In the One Piece World, apart from certain Devil Fruits related to souls, observing the soul was nearly impossible—yet in this world, his soul research might finally advance.
Though his thoughts wandered, his control of the scalpel remained flawless. A Quantum chip implanted in his brain, combined with magnetic manipulation, allowed him to hum a tune while guiding a hundred iron needles to carve the Ten-Thousand-Character Sutra onto a grain of rice.
Moments later, the surgery complete, Vegapunk injected Suikazan Fuguki with another shot—this time of the new Gene Modification Fluid.
This fluid incorporated genes from a wild summoning beast. The previous batch had used creatures from the sage sacred sites; this time the source was a truly wild specimen.
Orochimaru had encountered a colossal sperm whale at sea, nearly a kilometre long, virtually without natural predators. After a hard fight he had driven it off and, out of curiosity, collected some tissue.
Putting the scraps to use was convenient; stronger wild samples were scarce. With so little material on hand, a decent test subject was essential.
As the inheritor of Ryūchi Cave, Orochimaru had no personal need for wild summoning beasts. And while Vegapunk now controlled Suikazan Fuguki, he hardly cherished the man.
Control slots were precious; the controlled were expendable. With his methods, Vegapunk could craft an artificial human stronger than Fuguki whenever he wished—given time.
Fuguki had merely been a convenient tool for infiltrating Kirigakure, a task any Kirigakure Jonin could fulfil. Since he was unexceptional, Vegapunk simply repurposed him as experimental material.
Soon the gene modification took effect. Suikazan Fuguki roared, his frame ballooning once more. From just over two metres he shot up to four or five, muscles swelling, jaw broadening, skin turning slate-blue.
"Excellent—another success. It seems the genetic gap between sage-site summons and wild ones isn't large," Vegapunk remarked.
He promptly drew a blood sample from the dazed Fuguki, swirling the vial with evident satisfaction.
"There is a shift in Chakra, though. Wild summons merely awaken Chakra within themselves, whereas sage-site creatures absorb Natural Energy. Fluids derived from wild beasts mainly boost strength and Chakra volume, while those from sage sites enhance affinity for Natural Energy," he explained.
Orochimaru, who had also been studying Fuguki's Chakra, added his findings from the side.