(Note: Apologies for the oversight in posting the incorrect chapters. Thank you for your understanding)
Chapter 229 – Cellular Experiment
The difficulty of transplanting the Mangekyō far exceeded what either Uchiha Kei or Hyūga Ayaka had imagined.
Four full hours. That's how long it took them to complete the damned surgery.
When it was finally over, both were utterly drained. Kei was in better shape—he had only assisted, stepping in occasionally when Ayaka was at her limit. Ayaka, however, bore the brunt of it: her Byakugan had been active the entire time, her focus unwavering. By the end, her back was soaked through with sweat, though she never once faltered.
In the end, the operation could be considered a success. The surgical table was a bloodied mess, but Ayaka's Byakugan confirmed that the transplanted optic nerves had connected without issue. The two eyes, jammed together into one socket, showed no signs of damage.
As long as those two points held, Kei considered it a victory.
Still, he couldn't help but wonder—how exactly had Sasuke managed this in the original timeline? Obito had medical competence later on, but had he also mastered medical ninjutsu to this degree? Medical work like this was something Kei himself had never had the talent for.
After an hour's rest, Ayaka activated her Byakugan again to check.
"No issues so far. Maybe because they're blood brothers, the two Mangekyō housed in the same socket aren't rejecting each other at all."
"Is that so?" Kei formed a seal, testing.
Shuu's eyes opened—blood immediately streamed from the corners. The fused pupils were webbed with veins, their mismatched patterns glaringly grotesque. Kei even sensed a strange power stirring within.
The sight was unsettling, grotesque enough to sicken even someone as hardened as Kei. Ayaka, meanwhile, looked startled.
"What are you doing?" she demanded.
"Checking their condition," Kei replied, puzzled. "Why?"
"If you want to throw away four hours of work, by all means, keep going." Ayaka's voice was cold as she looked away, certain she'd wasted her time.
Kei silently withdrew his hand. Shuu's eyes slid shut again. "Don't just stand there—stop the bleeding!"
Ayaka ignored his tone and moved to Shuu's side, her hands glowing green. The bleeding subsided under her chakra, and she pressed gauze over his eyes to shield them and aid fusion.
"Don't do that again," she said firmly. "If you'd rather destroy them, just crush them outright—why risk sabotaging the entire procedure?"
"Fine, my mistake." Kei shrugged. "I'll be more careful. Still, I felt a strange resonance earlier. You noticed it too, didn't you?"
Ayaka nodded. "Yes. A resonance between the two pairs of eyes. But I haven't seen any signs of true fusion yet. Are you certain this method will work?"
How should I know? Kei thought bitterly. Should I admit I'm just experimenting?
He didn't answer. The original timeline had never described this process in detail. He had only theories, pieced together from fragments of knowledge.
Two main possibilities stood out to him:
1. Force both Mangekyō into the same socket and let them merge naturally.
2. Develop a jutsu capable of extracting ocular power completely, then infuse that power into another pair of eyes.
The second option was safer in theory, but Kei lacked the necessary foundation. The Transference Seal could indeed shift ocular powers, but it had limits—its storage capacity was too low, and lifting the seal risked losing power or triggering uncontrolled eruptions.
After many fruitless attempts to refine the concept, Kei abandoned the idea. That left him only with the first, primitive method—messy, risky, and uncertain, but the only viable path forward.
"This is the only method I can manage," Kei admitted with a sigh. "Maybe there are better ways, but I don't have the time or energy to pursue them. Can you estimate how long the fusion might take?"
"I can't," Ayaka said bluntly. "I'm not Uchiha. Besides, don't pretend you don't already have your own estimate."
"Fair point." Kei nodded. "By the way, a heads-up—Hiashi won't move until October. He's met me recently, so let him cool off for now."
"Understood. That's your decision." Ayaka had no objections. As long as Kei kept his word to her, she didn't mind. The materials she'd already gathered confirmed his claims, but more data meant greater certainty, and she would never refuse that.
As for her own path forward, she hadn't yet found a solution. She only knew one thing: she would never resort to genetic conditioning. Those so-called treatments—repairing and "activating" genes—were excruciatingly painful, with terrifyingly high mortality rates. Her studies made that much clear.
Ayaka had always been cautious, her habits shaped by years of surviving in a hostile world. She anticipated problems before they arose, prepared contingencies, and even now kept one wary eye on Kei himself.
"What about your progress with cellular medical ninjutsu?" Kei suddenly asked. "Are you ready for basic trials?"
"Basic trials?" Ayaka blinked, then narrowed her eyes. "Yes. What do you want me to test?"
"Cellular fusion." Kei's tone was calm, but his eyes gleamed.
"I want to measure how well foreign cells can merge with mine—the success rate, the mutation risk, the mortality odds."
He spoke evenly, but inside, Kei's blood was burning with anticipation.
For so long he'd held back. The White Zetsu cells had been in his possession for months, but he had restrained himself from integrating them. Yes, Obito was living proof they could work. Zetsu's cells were practically a risk-free version of Hashirama's cells.
But Kei could never shake the image of Obito's pale, grotesque half-body… or the face embedded in Madara's chest.
He had endured and waited, biding his time until he had a capable medical partner. Now, at last, he was ready to begin testing.
And when he did, he would do it properly.
He had no intention of turning into another Obito—or a pale mockery like Orochimaru.
The last thing Kei wanted was to wake up one day and find someone else's face sprouting grotesquely from his chest.
"If it were a woman's face, maybe I could tolerate it. But a man's? I'm not Madara, damn it!"
As Kei was grumbling inwardly, Hyūga Ayaka's calm voice pulled him back.
"Other people's cells… fusing with yours?" She studied him intently. "What exactly are you planning?"
Kei met her gaze, expression steady. "A study. An experiment. Can you do it? It's important—crucial to me. I wasn't planning on starting so soon. Originally, I meant to wait until we finished analyzing the eyes. But I've changed my mind. This will be part of laying the foundation."
Yes—Kei had shifted course.
At first, his plan had been to follow Madara's path, step by step, using the old man's success as a blueprint. But just now, when he saw Shuu's grotesque, twisted Mangekyō, he realized something.
It wasn't that Obito's path—integrating Hashirama's power before upgrading his Sharingan—was invalid. The problem was that Obito never had an Eternal Mangekyō in the first place.
By Kei's understanding, based on Madara's genetic "activation" and "repair," the absence of an Eternal Mangekyō was itself a form of genetic deficiency.
That explained why Obito, even as the Ten-Tails' jinchūriki, struggled so terribly—nearly consumed by the beast's will. Madara, in contrast, showed no such weakness. The difference had to lie in that missing piece—genes unrepaired, unawakened.
Ayaka thought quietly, then nodded. "I can try. But I can't guarantee success. Are you certain you have enough material? Without adequate samples for batch testing, I can't promise reliable results."
"I have more than enough," Kei replied with a thin smile.
Enough? More than enough. He had two full White Zetsu bodies at his disposal.
And another thought struck him:
Since one of his Mangekyō abilities could accelerate processes… perhaps he could even hasten the fusion and maturation of his Eternal Mangekyō.
The idea left him both excited and uneasy.