The departure from Uzushio Island was bittersweet.
Not for Kenjaku—he felt no particular attachment to the Uzumaki or their island home. But the knowledge he was leaving behind represented years of potential study, techniques he hadn't yet mastered, secrets that might have taken decades to fully uncover.
Still, it was time to move on.
Hiroshi met them at the outer harbor, his expression carrying the complicated mixture of disappointment and understanding that academics wore when promising students departed.
"You're certain you won't stay longer?" the senior scholar asked, for the third time that morning. "Your contributions to our research have been invaluable. The integration of curse techniques with sealing principles has opened entirely new avenues of development."
"I'm grateful for everything you've shared," Kenjaku replied, his tone carrying genuine appreciation beneath its characteristic smoothness. "But my path leads elsewhere now. There are other traditions to study, other knowledge to acquire. The work we've begun here will continue—just without my direct involvement."
Hiroshi nodded slowly, accepting the inevitable. "Will you return? Eventually?"
"Perhaps." It wasn't a lie, exactly. Kenjaku could imagine circumstances that might bring him back to Uzushio—though he could equally imagine circumstances that would make such a return impossible or undesirable. "The future is difficult to predict."
Miko was there as well, her young face trying and failing to hide the sadness of farewell. Her attraction to Kenjaku had never developed into anything significant—he had been careful to maintain appropriate distance—but she had clearly enjoyed their academic interactions.
"Take care of yourself, Shimoda-san," she said, bowing formally. "And if you ever need assistance with sealing techniques, the Uzumaki will remember your contributions."
"I'll remember that offer." Kenjaku returned the bow with precise courtesy. "Continue your studies, Miko. You have genuine talent. Don't let it go to waste."
The boat that would carry them to the mainland was already waiting, its crew preparing for departure. Kenjaku and Hana boarded without further ceremony, their supplies and scrolls already stored below deck.
As the island receded into the morning mist, Kenjaku allowed himself a final look at what he was leaving behind.
Three years of study. Hundreds of techniques analyzed and catalogued. A foundation of sealing knowledge that would serve his purposes for centuries to come. Relationships cultivated with one of the most valuable clans in the shinobi world.
Not a bad investment of time.
But there was so much more to do.
The journey to the mainland took most of a day, the currents that protected Uzushio requiring careful navigation even with experienced sailors. Kenjaku spent the crossing in meditation, processing everything he had learned and planning his next steps.
The Uchiha clan was his immediate destination.
Not for combat—not yet, anyway. The Uchiha were too valuable to antagonize carelessly, and Kenjaku had no desire to make unnecessary enemies. Instead, he intended to study them from a distance, observing their techniques and bloodline abilities, gathering intelligence that would prove useful in future encounters.
The Sharingan fascinated him from a theoretical perspective.
In the original Naruto timeline, the Uchiha dojutsu had been one of the most versatile abilities in existence. Basic Sharingan granted enhanced perception and the ability to copy techniques. Mangekyo Sharingan unlocked unique abilities specific to each user—Amaterasu, Tsukuyomi, Kamui, Susanoo. And the Rinnegan, the legendary eye of the Sage of Six Paths, represented power that approached the divine.
If Kenjaku could understand the spiritual mechanics behind these abilities, he might be able to replicate or counter them.
That understanding required proximity. Observation. Perhaps, eventually, direct study of Uchiha specimens.
But such opportunities would come in time. For now, patience was the priority.
"Master," Hana said, breaking into his contemplation, "what exactly are we hoping to accomplish with the Uchiha?"
Kenjaku opened his eyes, regarding his subordinate with mild interest. Her condition had stabilized somewhat during their time on Uzushio—the routine and structure had given her obsessive tendencies something productive to focus on. But the separation during his battle with Sukuna had damaged that stability, and she now watched him with an intensity that bordered on surveillance.
"Information," he replied. "The Uchiha possess abilities that will be relevant to my long-term plans. I need to understand how those abilities function, what their limits are, and how they might be countered or acquired."
"Acquired?"
"In theory. The Sharingan is a bloodline ability, passed through genetics. But genetics are simply another form of information storage—patterns encoded in flesh rather than paper. With sufficient understanding, such patterns can be replicated, modified, or transferred."
Hana's eyes widened slightly. "You want to give yourself the Sharingan?"
"I want to have the option." Kenjaku's smile carried no warmth. "I've never been satisfied with limitations, Hana. Every ability I lack is a potential vulnerability. Every technique I can't counter is a threat I can't eliminate. The Sharingan—and eventually, the Rinnegan—represent capabilities that I must either possess or perfectly understand."
"And if the Uchiha won't share their secrets?"
"Then I'll take them." The statement was matter-of-fact, carrying no particular malice. "But violence is inefficient. I prefer to acquire knowledge through study and observation whenever possible. Fighting draws attention, creates enemies, wastes resources that could be better spent elsewhere."
He turned to look at the approaching coastline, his mind already racing ahead to the challenges that awaited.
"Besides, the Uchiha are at war. They have more pressing concerns than a wandering scholar asking questions about their heritage. If I'm careful, I can learn what I need without ever becoming a priority for their attention."
They made landfall at a small fishing village, different from the one where they had originally departed for Uzushio. The coastline had changed during their three years on the island—villages destroyed, new settlements established, territorial boundaries shifted by the endless warfare that defined the era.
The Warring States Period continued, as brutal and chaotic as ever.
Kenjaku spent the first week simply observing, gathering intelligence about the current political situation. The information was both familiar and different from what he remembered of the original timeline.
The Uchiha-Senju conflict remained the dominant force shaping the region. Both clans had suffered significant losses over the past three years, their endless cycle of revenge and counter-revenge grinding away at their populations. But neither showed any sign of relenting—the hatred ran too deep, the blood debts too vast to ever be fully repaid.
Madara and Hashirama were now approximately thirteen years old—old enough to participate in combat, young enough to still be developing their legendary abilities. Reports described both as prodigies beyond anything their clans had produced in generations. Madara had supposedly awakened his Sharingan at an unusually young age and was already one of the Uchiha's most effective warriors. Hashirama's Wood Release had manifested in increasingly powerful forms, allowing him to shape battlefields in ways that defied conventional tactics.
They were becoming the legends that history would remember.
And Kenjaku intended to watch that process unfold.
But first, he needed to address his own development.
The training resumed with renewed intensity.
Kenjaku established a base camp in the mountainous territory between Uchiha and Senju lands—close enough to observe both clans, remote enough to avoid unwanted attention. The location offered natural barriers against intrusion and sufficient space for the kind of training that tended to reshape landscapes.
His physical enhancement had plateaued during the Uzushio years, but that didn't mean further improvement was impossible. It meant he needed new approaches.
The solution came from combining Idle Transfiguration with principles he had learned from Uzumaki sealing techniques.
Normal physical enhancement worked by optimizing existing structures—making muscles more efficient, bones more durable, nerves more responsive. But the human body had inherent limits, constraints imposed by evolution and biology that couldn't be exceeded through optimization alone.
Sealing techniques, however, could store and release energy in ways that transcended normal physical limitations. If Kenjaku could inscribe seals directly onto his own soul—seals designed to enhance physical output rather than simply contain or bind—he might be able to exceed the limits of conventional enhancement.
The theory was sound. The implementation was agonizing.
Each seal required careful design, precise inscription, and extensive testing before it could be safely integrated. The first attempt at a strength-enhancement seal nearly tore Kenjaku's arms off, the power output exceeding what his muscles could channel. The second attempt caused his legs to move faster than his nervous system could control, resulting in a spectacular crash that demolished a small cliff face.
But the third attempt worked.
The seal—inscribed onto the portion of his soul that governed physical force—allowed Kenjaku to multiply his strength output by a factor of three for short bursts. The enhancement stacked with his existing Black Flash modification, meaning that a single punch could now deliver impact equivalent to nearly eight times his baseline.
It wasn't enough to challenge beings like Kaguya or the eventual jinchuriki.
But it was progress.
The fourth seal enhanced his speed. The fifth, his durability. The sixth, his sensory perception. Each addition required days of careful work and recovery, but each addition brought him closer to the level of power he needed.
By the end of the second month at the mountain base, Kenjaku's physical capabilities had doubled from their pre-Uzushio levels.
And he was still improving.
The cursed energy development continued in parallel.
Kenjaku's reserves had grown substantially during his time on Uzushio, but growth wasn't the same as mastery. He needed to refine his control, develop new applications, expand the versatility of his existing techniques.
The Cursed Speech integration remained his most significant recent advancement. But the technique had limitations he was only beginning to understand.
Complex commands still caused backlash proportional to their difficulty. The more he asked of reality, the more it demanded from him in return. Simple instructions like "Stop" or "Die" could be delivered repeatedly without significant cost. But commands like "Transform into something harmless" or "Forget your own identity" extracted prices that made them impractical for regular use.
The solution, Kenjaku realized, was efficiency.
Instead of forcing reality to obey complex commands, he needed to break those commands into simpler components that could be chained together. Rather than saying "Transform" and trying to specify every detail of the transformation, he could say "Soften" to make flesh malleable, then use Idle Transfiguration to handle the actual reshaping.
The combined approach reduced backlash by nearly sixty percent while achieving the same results.
He developed similar optimizations for other command types. "Weaken" followed by physical attack instead of direct destruction commands. "Slow" to create openings rather than "Stop" to force complete cessation. "Confuse" to disrupt enemy coordination rather than trying to override their will entirely.
Each optimization made his Cursed Speech more sustainable for extended combat.
Each optimization brought him closer to the level of efficiency he needed.
"Master, someone is watching us."
Hana's warning came during the third month, interrupting a training session that had been progressing well. Kenjaku immediately shifted his perception, extending his senses to scan the surrounding area.
She was right.
A presence lurked at the edge of his detection range—shinobi, based on the chakra signature, but with an unusual quality that he couldn't immediately identify. They were maintaining careful distance, observing without approaching.
Uchiha, perhaps? Their territory was nearby, and a sorcerer performing landscape-altering training would certainly attract attention.
"How long?" Kenjaku asked quietly.
"At least an hour. Maybe longer. They're good at concealment."
Kenjaku considered his options. He could ignore the observer and continue training, accepting that his activities had been noted. He could flee, abandoning the base and relocating elsewhere. Or he could confront the watcher directly, determining their identity and intentions.
The third option carried the most risk—but also the most potential reward.
"Wait here," he told Hana. "I'm going to introduce myself."
He moved before she could object, his enhanced speed carrying him toward the observer's position with velocity that should have been impossible for a human body. The distance—nearly a kilometer—vanished in seconds.
The watcher didn't flee.
Instead, as Kenjaku burst into the small clearing where they had been concealed, the figure turned to face him with the composed readiness of a seasoned warrior.
It was an Uchiha. That was immediately apparent from the dark hair, the sharp features, and most importantly, the three-tomoe Sharingan that spun in both eyes. An adult male, perhaps thirty years old, wearing the standard equipment of a clan combat operative.
"You're faster than expected," the Uchiha observed, his voice carrying no particular concern. "The reports said you were unusual. They undersold the reality."
"Reports?" Kenjaku halted at a conversational distance, assessing the threat. The man's chakra reserves were substantial—jonin equivalent, at minimum. His body language suggested extensive combat experience and complete confidence in his abilities.
A dangerous opponent, by normal standards.
Not dangerous enough to threaten Kenjaku.
"We've been monitoring unusual activity in this region for several weeks," the Uchiha continued. "Explosions. Spiritual pressure fluctuations. Evidence of techniques that don't match any known tradition. The clan leadership wanted to know what was happening."
"And they sent you to find out?"
"They sent me to assess whether you're a threat." The Sharingan spun faster, analyzing Kenjaku's form with the dojutsu's enhanced perception. "So far, I'm undecided."
Kenjaku smiled his distinctive smile. "I'm not a threat to the Uchiha. Not currently, anyway. I'm simply a scholar, conducting research that requires... privacy."
"Scholar." The word carried obvious skepticism. "Scholars don't move at speeds that blur my Sharingan. Scholars don't reshape mountainsides with their training exercises. Scholars don't generate spiritual pressure that can be felt from five kilometers away."
"Perhaps I'm an unusual scholar."
"Perhaps you're something else entirely." The Uchiha's hand moved toward his weapon, though he didn't draw it. "Your chakra—if that's even what it is—feels wrong. Like something pretending to be human. Our sensors had difficulty even perceiving you properly."
Kenjaku's interest sharpened. The Uchiha's analysis was remarkably accurate, given the limited information available. Either this man was exceptionally perceptive, or the Sharingan's abilities exceeded what Kenjaku had expected.
Both possibilities were worth exploring.
"I'll make you an offer," Kenjaku said, deliberately relaxing his posture. "I have no hostile intentions toward the Uchiha clan. My research will be completed within a few more months, after which I'll relocate elsewhere. In exchange for being left alone during that period, I'm willing to share information that might be valuable to your leadership."
"What kind of information?"
"Strategic intelligence regarding Senju movements and capabilities. Details about sealing techniques that could neutralize Wood Release advantages. Tactical analysis of Hashirama Senju's fighting style, including potential vulnerabilities."
The Uchiha's eyes narrowed. "How would a 'scholar' possess such information?"
"I told you—I'm an unusual scholar. One who values knowledge above all else, regardless of its source or implications." Kenjaku spread his hands in a gesture of openness. "The Uchiha-Senju conflict doesn't concern me either way. But if sharing what I know buys me the privacy I need, I'm happy to contribute to your war effort."
There was a long moment of silence as the Uchiha considered the offer. His Sharingan continued to analyze, searching for deception or hidden threat.
Finally, he spoke.
"I'll convey your offer to the clan leadership. They'll decide whether to accept." He began backing away, maintaining careful awareness of Kenjaku's position. "But understand this—if you prove to be a threat, we will respond accordingly. The Uchiha do not tolerate dangers in our territory."
"Of course." Kenjaku's smile remained pleasant and unthreatening. "I wouldn't expect anything else from such a distinguished clan."
The Uchiha vanished, his speed impressive by shinobi standards if not quite matching Kenjaku's enhanced capabilities. Within moments, his presence had faded from detection range, heading in the direction of the clan's main territory.
Kenjaku remained in the clearing, processing the encounter.
The contact was earlier than he had planned, but not necessarily problematic. The offer he had made was genuine—he did possess information that would be valuable to the Uchiha, and sharing it cost him nothing significant. If they accepted, he would gain access to their territory under semi-legitimate pretenses. If they refused, he would simply relocate and approach the situation differently.
Either way, progress was being made.
He returned to find Hana in a state of barely controlled agitation.
"Master, you just—you went alone—what if it had been a trap—what if—"
"It wasn't a trap." Kenjaku began dismantling his training equipment, preparing for potential relocation. "It was reconnaissance. The Uchiha noticed my presence and sent someone to investigate. I've offered them a trade: information for privacy."
Hana's distress slowly subsided as the practicality of his approach became clear. "Will they accept?"
"Probably. They're at war, and any advantage against the Senju is worth pursuing. My information could save Uchiha lives—not something their leadership will dismiss lightly."
He paused, considering the implications.
"This might actually accelerate our plans. If the Uchiha accept my offer, I'll have a pretense for entering their territory directly. That means observation opportunities I wouldn't otherwise have access to. Potential study of their techniques and bloodline abilities."
"And the risks?"
"Manageable. The Uchiha are dangerous, but not uniquely so. Their Sharingan grants perception and copying abilities, neither of which threatens my core techniques. As long as I don't give them reason to view me as an enemy, they should prove useful rather than problematic."
Hana nodded, accepting his assessment. Her trust in his judgment had long since become absolute—if he said the risks were manageable, then they were manageable.
"What do we do now?"
"We wait. If the Uchiha accept, they'll send someone to negotiate terms. If they refuse or decide to attack, we'll know by their approach. Either way, the response should come within a few days."
He finished his preparations and settled into a meditation posture.
"In the meantime, I'll continue my training. Becoming stronger is never a waste of time—especially now."
Because Kenjaku knew, despite his victory over Sukuna, that he was not yet strong enough.
The King of Curses had been an apex predator, a being of overwhelming power who had terrorized generations of sorcerers. Defeating him had been a significant accomplishment—but it had also revealed the limits of Kenjaku's current capabilities.
He had won through preparation and surprise, not through superior force.
Against opponents who knew his techniques, who could prepare counters to his approaches, who possessed power approaching Sukuna's level—victory would not come so easily.
And such opponents would emerge.
That was the nature of power in any world. When one apex predator fell, others rose to claim the vacant territory. Sukuna's erasure had created a vacuum that ambitious beings would inevitably try to fill.
Madara Uchiha was one such being. His eventual mastery of the Sharingan's full potential would make him one of the most dangerous individuals in shinobi history. The Rinnegan, when he finally awakened it, would grant abilities that approached the divine.
Kenjaku needed to be ready for that confrontation.
Obito Uchiha was another threat, though he hadn't been born yet. His Kamui technique would make him essentially untouchable during activation—a defense that Kenjaku hadn't yet developed a counter for.
Kenjaku needed to solve that problem.
The Otsutsuki were perhaps the greatest long-term danger. An entire clan of dimension-hopping parasites, each possessing power that exceeded most shinobi legends. Kaguya alone had required the combined efforts of Naruto, Sasuke, and the reincarnated Hokages to seal—and even then, sealing rather than killing had been the only option.
Kenjaku needed to become capable of challenging such beings.
And then there were the threats he couldn't predict.
Other transmigrators or reincarnators who might exist in this merged world. Beings from the jujutsu side of history who hadn't appeared in canon. Natural evolutions of power that the merging of two universes might produce.
Any of these could emerge at any time, presenting challenges that Kenjaku hadn't prepared for.
The only solution was constant improvement.
More power. More techniques. More options for every conceivable situation.
Arrogance was the enemy. Complacency was death. Sukuna had fallen because he believed himself invincible, and Kenjaku refused to repeat that mistake.
No matter how strong he became, he would always assume there was someone stronger.
No matter how prepared he was, he would always assume there were threats he hadn't anticipated.
No matter how complete his victory seemed, he would always prepare for the next challenge.
That was what separated him from the monsters who had come before.
That was what would allow him to endure when they had all been forgotten.
The Uchiha response came on the fourth day.
Not a single scout this time, but a delegation of three: the same Sharingan-user who had first made contact, accompanied by two others who radiated the authority of senior clan officials. They approached the camp openly, making no attempt at concealment.
Kenjaku met them at the perimeter, Hana positioned behind him in a supporting role.
"The clan has considered your offer," the lead Uchiha announced. "We're interested in your information—but we have questions first."
"I expected as much. Please, ask."
"Who are you, really? 'Shimoda Kenichi' doesn't appear in any records we can find. The Shimoda clan exists, but they claim no knowledge of anyone matching your description."
Kenjaku had anticipated this. The cover identity he had been using was thin, designed more for Uzumaki academics than for clan intelligence operations.
"Shimoda Kenichi is an assumed name," he admitted freely. "My true identity is complicated and largely irrelevant to our potential arrangement. What matters is that I possess knowledge valuable to your clan, and I'm willing to share it in exchange for considerations that cost you nothing significant."
"What considerations, specifically?"
"Privacy to continue my research without interference. Access to your territory for observation purposes—I'm a scholar of combat techniques, and your clan's martial traditions interest me academically. And eventually, possibly, access to records regarding your bloodline abilities."
The officials exchanged glances. The final request had clearly been noted as the most significant.
"You want to study the Sharingan?"
"I want to understand it. Not to steal or replicate—I have no Uchiha blood, and the dojutsu cannot be transferred to those outside your lineage." The lie came smoothly, supported by body language that radiated scholarly curiosity rather than predatory interest. "But the theoretical principles underlying your abilities represent some of the most sophisticated spiritual engineering in existence. Any serious student of such matters would want to study them."
Another exchange of glances. The lead official—the one who had first made contact—spoke again.
"We'll grant your request for privacy and territorial access. Our patrols will be informed that you're an... allied researcher, operating with clan sanction. In exchange, you'll provide the strategic intelligence you mentioned, delivered in writing within one week."
"Agreed."
"The matter of Sharingan research is more complicated. Such knowledge is closely guarded, for obvious reasons. If you prove trustworthy over time, limited access might be arranged. But that will require demonstrated value to the clan beyond what you've already offered."
Kenjaku nodded, unsurprised. "I understand. Trust must be earned. I'm prepared to invest whatever time is necessary."
The negotiation continued for another hour, hammering out specific terms and establishing protocols for communication. By the time the Uchiha delegation departed, Kenjaku had secured everything he had hoped for—and planted seeds for future developments that the clan couldn't yet imagine.
Hana waited until the officials were well out of range before speaking.
"They're suspicious of you."
"Of course they are. They'd be fools not to be." Kenjaku began preparing the promised intelligence documents, drawing on knowledge that his meta-awareness provided. "But suspicious isn't the same as hostile. As long as I provide value and don't threaten their interests, they'll tolerate my presence."
"And when that changes?"
"Then we'll adapt." He glanced at her with something approaching warmth. "That's what we do, Hana. We adapt, we grow, we overcome whatever challenges emerge. The Uchiha are powerful, but they're not insurmountable. Nothing is."
He returned to his work, mind already racing ahead to the opportunities this arrangement would provide.
Access to Uchiha territory meant observation of their techniques in action. It meant potential contact with young Madara, whose development would be fascinating to watch. It meant intelligence gathering that would prove invaluable in future confrontations.
And it meant another step toward the power he needed.
Because the training would continue. The improvement would persist. The endless climb toward strength sufficient to challenge any threat would never stop.
Kenjaku had killed a king.
Now he needed to become something that even kings would fear.
And he was only getting started.