"It looks like your body is finally adapting to the new cellular structure."
Hyūga Aya glanced at the latest test report in her hands, comparing it mentally to prior records. As always, the document would be destroyed after reading—it was meant solely for Uchiha Kai and her to review.
Kai's integration with the transplanted cells had gone better than expected. The acute rejection phase had lasted less than three days this time, a marked improvement compared to the week-long symptoms during the second experiment. If not for Kai's exceptional regenerative ability—likely tied to his Sharingan and genetic resilience—this progress wouldn't have been possible.
"The hematopoietic response held steady," Aya murmured, flipping the clipboard closed. "And the fusion with the white cell sample seems more stable now."
Kai gave a faint nod. "We're lucky. If the graft didn't take, we'd be starting from zero again."
"Luck?" Aya snorted lightly. "You call this luck?"
"It's better than failure."
Though they'd only completed three experiments so far, the cumulative results were promising. Kai's chakra capacity, while not drastically altered beyond natural growth, had noticeably increased.
"I'd estimate I've got twice the chakra I had back on the battlefield a year ago," Kai said as he lit the report on fire with a flick of katon chakra. "And the adverse reactions are getting shorter."
"That's true," Aya admitted. "For something borderline illegal and definitely unethical, we're doing surprisingly well."
Kai shrugged. "It's progress. That's all that matters."
As Aya packed away her tools, she glanced at him. "You mentioned last time you wanted to visit someone. Who was it again?"
Kai didn't hesitate. "Orochimaru."
Aya blinked. "You what?"
"Imai Kenta and I went to... pay him a visit. It wasn't the friendliest meeting."
Aya shook her head slowly. "I'm surprised you two came back at all. The man's practically a ghost story wrapped in a lab coat."
"Orochimaru's a legend," Kai agreed. "But that doesn't make him invincible. He's powerful, unpredictable—but not untouchable."
"Still, you're playing with fire. He's not the kind to forget people who cross him."
Kai smirked faintly. "Neither am I."
Aya folded her arms. "So? What did you find on that 'visit'?"
"Evidence of human experimentation," Kai said bluntly. "And a list—genuine this time. I gave it to Kenta. The research has ties to someone in his family."
Aya raised an eyebrow. "Kenta? That civilian-born swordsman?"
"He's not as ordinary as he seems."
Aya narrowed her eyes. "You're telling me he's hiding something?"
Kai met her gaze. "Let's just say his ancestry might include a certain forgotten clan. One the Hokage's office doesn't like to talk about."
"…Senju?" Aya asked, the name barely a whisper.
Kai said nothing, which was answer enough.
Aya leaned against the wall, frowning. "So that's where those white cells came from. The connection between him and Orochimaru's research… it all links back to the First Hokage."
"There are rumors," Kai said. "That Orochimaru got access to something buried in the Land of Grass. Half a body. It had the same eyes as me."
Aya inhaled sharply. "You mean... the Mangekyō?"
Kai nodded slowly.
Aya looked disturbed. "And you think that corpse had Senju DNA? You think Orochimaru—"
"Had been experimenting with it, yes. But the materials I used didn't come from Orochimaru directly. I got them during a different mission."
Aya's mind worked quickly, tracing the connection between Kenta's bloodline, Orochimaru's experiments, and Kai's growing power. She recalled names: Uchiha Osamu, Uchiha Yugi… now Kenta too?
"Then these cells," she said, "the fusion—you're building something with purpose. You're aiming for... what? Eternal Mangekyō?"
Kai didn't confirm, but the look in his eyes said everything.
She changed the subject. "And what about Iori? The assistant?"
"She's doing fine," Aya replied. "I plan to let her start on cell extraction soon."
"Make sure she knows what to say—and what not to."
Aya nodded. "She's loyal. Scared enough of me, and respectful enough of you."
"Good." Kai stood. "By the way, Kenta wants a private meeting. Probably to offer deeper cooperation."
Aya tilted her head. "And you'll go, of course."
"If he has something of value to offer. I don't waste time on people who don't."
Aya gave a soft laugh. "And here I thought you were starting to mellow out."
Kai paused at the door, then looked back. "You're still working with me. That proves I've changed—at least a little."
Aya's smile faded into something more thoughtful. "I've seen enough of Konoha's secrets to know how fragile everything is. You and I… we've crossed too many lines to go back."
"Then we don't go back," Kai said. "We go forward."