Hashirama Senju's cells are extremely volatile; ordinary people simply cannot absorb them.
Without a corresponding Six Paths bloodline, even a Kage-level shinobi like Danzō needed a large number of Sharingan to maintain the Yin-Yang balance (and conversely, sustaining that many Sharingan required the support of the First Hokage's cells). Even then, he had to rely on powerful sealing techniques to suppress the side effects—otherwise, the chakra consumption would become unbearable.
Put bluntly: unless you possessed Six Paths lineage, fusing with Hashirama's cells meant one thing—being devoured by them. At best, you could integrate a modified variant, like the White Zetsu clones. But even with the bloodline, withstanding the fusion remained incredibly difficult.
Fugaku, despite being Kage-level in strength, possessing massive chakra reserves and both Mangekyō Sharingan, still had a near-zero chance of success when attempting to fuse with Hashirama's cells.
Such was the terrifying nature of Asura's strongest reincarnation.
Of course, the cells being implanted into Fugaku now were far from their raw, original state. They had undergone countless modifications. The earlier ominous explanations had merely been a tactic—to amplify Fugaku's emotional investment and push his Sharingan and Yin chakra to their maximum output.
"Alright, no need to be so afraid. It's not as bad as Orochimaru makes it sound,"
said Yuki Yoru, watching Fugaku's nerves with a faint smile.
"All you need to do is fully activate your ocular power—suppress it, harmonize with it. That's all. You'll be fine."
"Understood."
Fugaku nodded firmly, inhaled deeply, and activated his three-tomoe Sharingan, which swiftly spun into Mangekyō form.
Seeing him ready, Yoru nodded to Orochimaru, who disinfected his hands, inserted a few needles, and injected several unknown fluids into Fugaku's body.
Then, Orochimaru picked up a scalpel and made a shallow incision over Fugaku's abdomen, simultaneously using chakra to stimulate the internal chakra pathways, increasing their activity.
Cell fusion wasn't something that could be done carelessly—especially not with Hashirama's cells.
Even after generations of modification, successful fusion still required implanting the cells into one of the body's regions where chakra pathways were most densely concentrated. Only then could the host draw on enough chakra to suppress and integrate the foreign cells.
After fusion, this also ensured full control over the new power—as if it were part of one's own body.
In the human body, the eight areas where chakra pathways were most densely concentrated were known as the Eight Gates: two at the sides of the brain, one at the heart, and five spread across the torso and lower body.
This was the same system used in the infamous Eight Gates Forbidden Jutsu, which forcibly unlocked chakra restraints for massive power.
For Fugaku specifically, the most ideal transplant zones were:
The two cerebral points: the "Gate of Healing" (Kyūmon) and "Gate of Opening" (Kaimon)—where Uchiha Yin chakra concentrated most densely;
The "Gate of Death" (Shimon) near the heart—source of the body's ultimate chakra potential.
Madara Uchiha had implanted Hashirama's original cells directly into his heart, allowing him to wield Wood Release nearly on par with Hashirama himself.
By contrast, Danzo and Obito, who implanted cells in their arms, could barely use Wood Release without risk of backlash.
But they had no choice—Danzo lacked the bloodline, and Obito had lost half his body.
In Fugaku's case, his goal wasn't to acquire full Wood Release, merely to restore and boost his Mangekyō. So, Orochimaru chose a safer zone: the "Gate of Wonder" (Keimon) near the lower abdomen—the seventh gate.
This ensured that even if the transplant failed, the infected flesh could be cut out quickly—preventing Fugaku from turning into a giant tree.
With the site chosen and prepared, Orochimaru picked up a glowing white clump of tissue, and with his forceps, implanted it into Fugaku's abdomen. He then dripped in a cocktail of nutrient fluids, inhibitors, and chakra stimulants to trigger fusion.
"Aaahhh!"
As chakra surged, the white tissue began to writhe, extending root-like tendrils into Fugaku's flesh like a tree taking root.
The chakra monitors on the lab walls spiked—alarming fluctuations.
Fugaku trembled violently, his pupils dilated, and his Mangekyō began spinning madly.
His Yin-based Uchiha chakra surged toward the implant site—countering Hashirama's cells as they began their invasion.
"Stay calm. Don't tense up too much. The key is how well your chakra and ocular power integrate with the graft. Don't resist it violently,"
Yoru said calmly. He had overseen this procedure before—on Shisui—and understood the process thoroughly.
Fugaku's reaction was clearly too intense, but Yoru's steady voice brought him some relief.
The tissue at Fugaku's abdomen continued pulsing, trying to assimilate the surrounding flesh.
But soon, Fugaku's chakra started to fight back effectively. The aggressive white mass began to retract, nestling itself into his waistline. Soft green chakra light emanated from the site.
The chakra had stabilized.
Uchiha Yin chakra had provoked the Yang chakra inside Hashirama's cells, causing it to release.
The two polar forces clashed and merged. It was not a painless process.
Fugaku's face contorted in pain. As the fusion deepened, the implanted tissue twisted into a humanoid face—ashen, stoic, and unnatural.
Even Orochimaru looked briefly unsettled, though he didn't seem surprised—he'd seen it before.
"Keep channeling your eyes—let it stabilize..."
Yoru glanced at the monitors and nodded approvingly.
"Just a bit longer… you're almost there."
...
Meanwhile — Amegakure
On the highest tower of Amegakure, a red-haired figure stood, surveying the city below.
This was not Pain the god, but the man behind the eyes—Nagato, wielder of the Rinnegan.
"How do you feel?"
Konan, wings of paper unfurled, hovered silently behind him. Her gaze lingered on his vibrant red hair, now full of life again.
The battle in the Land of Iron had nearly destroyed him. He had been pushed to the brink of death. But it had also been the trigger for rebirth.
Thanks to the White Zetsu graft and the infusion of Hashirama's cells, Nagato's legs were restored, and his strength now far exceeded his former self.
To Konan, it was like looking at the old Nagato again—the one from before everything had gone to hell. His aura was like a fusion of the Nagato she once knew and Yahiko.
"I feel great," Nagato said, smiling faintly. "Maybe I should've agreed to Zetsu and Madara's proposal sooner.
Hashirama's cells harmonize with my Rinnegan and Uzumaki blood perfectly. I feel alive again."
He turned to Konan.
"If I'd done this earlier, maybe we could've avoided all the pain."
"Our teacher said once: all suffering exists to prepare us for a better version of ourselves," Konan replied. "Without it, we wouldn't be who we are."
"True. But now… no more pain for us."
"I've been reborn. This is the body of a god.
Even Yoru Yuki no longer poses a threat."
Nagato's voice brimmed with confidence. The glow of the Rinnegan shimmered with power.
"Nice confidence—but you're still far from ready to defeat Yuki Yoru."
The voice came from behind, sharp and cutting.
Obito, disguised as "Madara," stepped through a swirling distortion, with Zetsu at his side.
"What do you want, 'Madara'?"
Nagato turned, expression unreadable. Konan narrowed her eyes but remained silent.
Despite their tension, Nagato's survival had been made possible by Obito and Zetsu's interventions.
"You've recovered, yes. But don't let it go to your head,"
Obito said in a low rasp, his rage barely masked.
"You fought Yoru once and lost. Nothing's changed. Not even a restored body will close that gap.
Even with Wood Release, it's not enough."
He tossed Nagato a scroll.
"Three years ago, you fought him in the Land of Iron. While that was happening, things happened in Konoha that I didn't tell you—until now."
Nagato opened the scroll—and his expression darkened immediately.
The so-called god of Amegakure was clearly shaken.
"Don't bother doubting the intel. The site still exists—Konoha's largest forest reduced to ash by residual chakra.
He's surpassed both my prime and even Hashirama's.
He's nearing Sage of Six Paths territory."
"If you want to beat him… you're not even close."
Nagato closed the scroll silently.
"So why are you here? Just to undermine me?"
"Not at all," Obito replied. "Besides humbling you, I'm here to help you defeat him."
"Help?" Nagato's heart skipped.
Obito nodded.
"We lost a lot of tailed beast intel. But I found a new way forward."
He threw another scroll.
"You should know Hiruko and his Chimera Jutsu.
He tried to ascend using Steel Release, Swift Release, Dark Release, Storm Release, and the Sharingan—to become an immortal ninja."
"I've developed something more refined. A true path to transcendence."
Nagato frowned as he opened the scroll and examined it closely. The more he read, the tighter his brows furrowed.
"You, with the Rinnegan, already possess the Sage's eyes. You are his rightful successor. What you lack… is his blood. If you gather all of the Six Paths bloodlines and fuse them through Chimera Jutsu, then you won't just carry his will or his name," Obito said, his voice steady, deliberate. He paused, letting the silence hang for a moment. "You will become something new. A Sage in a new form. I call it… the Living Six Paths."
"Uchiha. Hyūga. Uzumaki. Kaguya. Senju," he continued, listing them with almost reverent intensity. "Sharingan, Byakugan, Wood Release, Shikotsumyaku, and the life force of the Uzumaki bloodline. Two are already yours—Wood Release and Uzumaki vitality. I hold the Sharingan and the Byakugan. All that remains… is the Shikotsumyaku."
"Once you possess that final piece, and the day of the celestial anomaly arrives, you'll ascend. You'll become the Living Six Paths. No longer a successor. No longer a vessel. But a god—reborn in the flesh."
Behind the spiral mask, Obito's Sharingan flared—blood-red, burning with obsession and vision. "With that power, Yuki Yoru will fall. And you… will bring peace to the world."