Chapter 232 – Good News and Bad News
While Konoha's "Four Giants" conspired on how to deal with the Fourth Hokage, Uchiha Kei was immersed in his own experiments.
After Hyūga Ayaka drew nearly 480 milliliters of blood from him, Kei had taken some time to recover. Fortunately, the ex vivo cell fusion experiment she was conducting didn't require him to take further risks—though it was time-consuming and far more difficult than she'd initially anticipated.
It took her almost two weeks before she produced her first viable sample.
The results, however, were worse than before.
The percentage of non-reactive outcomes hadn't improved—it had actually dropped. The failure rate had risen, with more samples being outright devoured by the foreign cells.
Kei could only sigh at the report. At least he hadn't been foolish enough to assume he had Obito's kind of miraculous luck. Otherwise, he'd probably already be bleached-white all over, or worse—sprouting tree branches from his body.
After two days of purging the failures and discarding useless byproducts, less than 200 milliliters of Kei's original blood remained usable from the initial 480.
"The real question," Kei murmured, staring at the samples, "is whether these cells can survive in my body at all—and if they do, what they'll actually do to me."
He was painfully aware rejection was likely, perhaps leaving him weakened for weeks. But the bigger uncertainty was survival. These cells weren't purely Senju Hashirama's anymore; they'd been altered through fusion with Kei's own.
And their numbers were pitiful compared to the trillions of cells already inside his body. In terms of progress, the cell experiment was decidedly bad news.
But there was good news too.
Uchiha Shuu's transplanted Mangekyō Sharingan had finally begun to fuse with Uchiha Yuu's.
Ayaka had been the first to notice it. Even through thick gauze and closed eyelids, her Byakugan had pierced the concealment. The two pairs of eyes were… merging.
The fusion rate wasn't even at five percent yet, but the eyes were visibly adhering together, drawn by some mysterious force that refused to let them separate.
What shocked Ayaka most was that neither pair had suffered damage. It was as though they'd always been meant to exist as one.
"Has the report come out yet?" Kei asked softly, glancing at Shuu lying motionless in the monitoring equipment.
"It has," Ayaka replied coolly. "Which do you want first—the genetic findings or the ocular ones?"
"Give me the least useful first," Kei decided after a pause. Better to get the bad news out of the way—it made the good news sweeter.
"You might be disappointed," Ayaka said, glancing at him, "because this time, everything looks… pretty good."
Kei blinked, then allowed himself a rare smile.
All good news?
Maybe, just maybe, his luck wasn't so bad after all.
Ayaka didn't keep him waiting. "Through Byakugan observation and comparison with several days' worth of Shuu's extracted genetic samples, your theory is confirmed."
She kept her explanation simple, and Kei wasn't slow. He quickly pieced together what she meant.
His method was correct. The two Mangekyō were fusing—and more than that, the process had already begun to generate a strange new energy.
It was similar to chakra, yet not quite. Under its influence, Shuu's body was producing entirely new cells—cells Ayaka could track with her Byakugan.
Not because her dōjutsu had grown sharper, but because these cells were so unusual, carrying a bizarre and potent energy of their own.
And under their influence, Shuu's genes were changing. Previously dormant sequences were beginning to respond. Ayaka had even noticed something peculiar.
"Uchiha Shuu's genetic chain appears incomplete," she reported flatly. "As these cells proliferate, the gaps are becoming clearer. I even detected a fracture near the front of his genetic sequence."
"You found a fracture?" Kei's eyes narrowed in surprise.
"Yes," Ayaka nodded. "I can't say whether it's unique to him or a general trait. I only have his sample to work with, after all."
Kei wasn't shocked. Compared to the Hyūga, the Uchiha genetic chain was fragmented. Their lineage had been fractured ever since Hagoromo Ōtsutsuki's descendants split.
Indra and Ashura—two sons who each inherited only part of the Sage's power. That genetic break was still etched in their bloodline.
"You must've cross-checked with others," Kei said at last, his tone calm though his mind was racing. "Otherwise you wouldn't be so certain."
"I did," Ayaka admitted without hesitation. "Not just you—I checked Yuu as well. Both of you are… recessive. Hidden traits, inaccessible. That's why I made my conclusion."
Kei sighed. "Fair enough. I've known this problem for a long time. The fact you brought it up shows you genuinely want to help—or at least, to hold me to my promises."
His voice hardened slightly. "And I'll keep my promises. I wouldn't have told you so much, or let you near so many secrets, otherwise. I certainly wouldn't have marched into the Hyūga compound to take you in broad daylight."
Ayaka nodded, saying nothing more.
She could tell Kei wasn't stringing her along. If anything, his openness exposed him to risk—and that in itself was a kind of protection for her.
If something happened to her under Kei's watch, he couldn't possibly escape the consequences.
It was a dangerous arrangement, but it guaranteed her survival.
Ayaka knew now that she'd proven her worth. Otherwise, this calculating Uchiha would never have gone to such lengths.
And she had value—her data, her Byakugan, and her insight. Kei might have backup plans, like grooming the orphan girl Iori, but for now, Ayaka was irreplaceable.
Iori might be bright—the most talented child in the orphanage—but she was still too young, too raw. Her foundations were far too weak.
Ayaka, by contrast, was indispensable.
Hyūga Ayaka had no real background in medical ninjutsu.
But she was still a shinobi—more than that, a Hyūga clan shinobi.
The Hyūga fighting style, centered on the Gentle Fist, demanded an intimate knowledge of the human body.
With the Byakugan at her disposal, and her natural intelligence, Ayaka had managed to quickly meet Uchiha Kei's expectations.
"It seems the defect runs through your clan's genes as a whole," Ayaka murmured, studying Kei with a thoughtful look. She didn't press further, though.
"Probably," Kei admitted evenly. "But there are ways to compensate. Anyway—this special energy you mentioned. Is it possible to extract it?"
"Unlikely." Ayaka shook her head. "That power is strange. I lack the sealing techniques or the skill for such a task. Even if we had the right seal, success isn't guaranteed. It resembles chakra, but… it's not the same."
Kei frowned. That wasn't the answer he'd hoped for.
So it's like the Yin Release born from the Mangekyō—an energy born of emotion, impossible to separate or isolate.
Still, he had come too far to back down now.
After a pause, Kei's eyes narrowed. "…Then, is the answer once again in the cells?"
"Yes," Ayaka confirmed. "We can't extract that force directly. But the cells already infused with it are tangible, real. Their numbers are small, but they can be harvested. That's a far more reliable path than trying to pull out the raw energy itself."
"I see." Kei exhaled slowly, then gave a reluctant nod. "Fine. We'll proceed with experiments. Keep it ex vivo—we'll measure the actual effects first."
There was no other choice. Kei couldn't help but feel a flicker of irony.
He'd originally pushed Ayaka into studying cellular medical ninjutsu for the sake of White Zetsu's cells.
Who would've thought that even the byproducts of Eternal Mangekyō fusion would end up needing the same research?
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