"Carefully sense how much your power has increased, Kaien."
After a moment of surprise, Orochimaru quickly regained his composure, slipping back into the professional mindset of a scientist.
This was a perfect opportunity to collect data.
Regardless of whether Kaien had an exceptional trait for Sage Mode training, the data alone was of immense research value.
That tiny trace of senjutsu chakra from Manda's body had actually been absorbed and utilized by a ninja—did this suggest that chakra could be transferable between sources?
"I can feel it… I'm stronger. Faster, too. And the quality of my chakra has improved significantly."
That was Kaien's most immediate and tangible sensation.
As for anything else, he didn't bother explaining.
The effect of [Spirit of Nature] was even better than he'd expected.
Once his body adapted to the senjutsu chakra, [Spirit of Nature] seemed to fully awaken. In Kaien's perception, the natural energy in the environment was eagerly surging into his body. He didn't even need to manually balance it with his chakra—the two energies coexisted like old friends, blending seamlessly without conflict.
"What about ninjutsu? Has it received a boost as well?" Orochimaru asked again.
According to intel from Jiraiya, Sage Mode enhanced the entire body comprehensively, with ninjutsu growing several times more powerful.
"My ninjutsu definitely feels stronger... and even my genjutsu seems to have improved to some extent."
Kaien reported his initial findings truthfully.
Then, he quietly deactivated Sage Mode.
The senjutsu chakra drawn from Manda had already been depleted. From this point on, he would have to sustain Sage Mode entirely through absorbing natural energy himself.
"It's just... the duration's a bit too short, Orochimaru-sensei."
The purple markings around Kaien's eyes faded, and he deactivated his Sharingan as well.
"I see. Then Manda's senjutsu chakra must be limited," Orochimaru murmured, rubbing his chin thoughtfully.
How long would it take for Manda to recover enough to participate in the next experiment?
Even a top-tier serpent like Manda only possessed that much chakra—Kaien had managed to maintain Sage Mode for barely a minute.
Stronger serpents—those who could take human form. But summoning them would be rather impolite.
For now, Orochimaru could only organize the collected data and wait for Manda's chakra to replenish before conducting further tests.
Kaien, meanwhile, turned his focus to studying the effects of his unique trait, [Spirit of Nature].
He had discovered that, with a bit of conscious effort, he could directly enter Sage Mode—no need to travel to one of the three sacred lands for training.
After acquiring Manda's senjutsu chakra, his [Summoned Phantom Beast] ability could also act as a kind of chakra reservoir for Sage Mode.
He could simulate senjutsu chakra within the phantom beast and feed it to his real body.
What was this? A natural energy jinchūriki?
Or maybe... the fourth Great Sage?
Unfortunately, the phantom beast was currently stationed in Sunagakure, working to sway Sasori of the Red Sand. For now, Kaien could only use its basic ability to absorb chakra.
Thus, he decided to focus entirely on developing [Spirit of Nature].
...
Time passed in a blur.
Over the next five years, Kaien maintained a low profile. He completed the occasional mission, assisted Namikaze Minato with the development of the Nine-Tails Chakra Mode, and casually harvested affection from within Konohagakure—while steadily growing stronger.
And today marked his seventeenth birthday.
With the shinobi world in a relatively peaceful state, most of Konoha's powerful ninja were on leave. Anyone even remotely familiar with Kaien showed up to celebrate.
Fortunately, his home was large enough to accommodate them all.
"Today really is a good day."
Kaien slowly opened his eyes. The Mangekyō pattern faded, leaving only three tomoe, drifting slowly like ink in water.
But almost immediately, the tomoe began to change again—hinting at a new evolution.
The dark marks linked together, and Kaien's Sharingan underwent a transformation. The six-petaled Mangekyō design bloomed into a nine-petaled pattern, encircled by ornate, regal lines radiating from the center.
His eyes finally stabilized.
If Uchiha Madara had been present, he would've instantly recognized what this meant.
The Eternal Mangekyō Sharingan.
The ultimate ceiling of the Uchiha clan's dōjutsu.
Through five years of accumulation, Kaien's Mangekyō had evolved naturally into the Eternal Mangekyō—without any pain or side effects.
"Feels like I've gotten a little too strong," Kaien murmured.
With a single thought, he could summon his Complete-Body Susanoo. There wasn't a single shinobi alive who could defeat him.
And that was before considering his Sage Mode.
Or the greatest reward of his five years of effort—
[Timeless Flow]: Your bloodline potential has been awakened again. You are no longer bound by your clan's natural limits. Your future is full of endless possibilities. You possess a long lifespan, tracing back to the source of all things, constantly evolving. Current ceiling: Ōtsutsuki Clan.
This new trait was the result of upgrading [Eternal Light] to a golden-tier trait using all the affection he'd accumulated over the past five years.
The upper limit was unknown. The Ōtsutsuki Clan had both strong and weak members, but Kaien was certain of one thing—
...
Reason number one million to carry out the Eye of the Moon Plan.
He now possessed the ability to create chakra fruits—and the power to consume them, pushing himself to an even higher plane of existence.
All that remained was to gather the Ten-Tails. Then, using the phantom beast to absorb its core informational essence—its origin chakra—Kaien could become the perfect Ten-Tails jinchūriki.
And since the Ten-Tails was simulated by the phantom beast, there would be no hidden backdoors planted by other Ōtsutsuki members.
He could use that power without reservation.
At this point, if Kaien wanted to call himself Ōtsutsuki Kaien, no one could argue.
He reined in his chakra and stepped out of his room, wearing a faint smile.
Today was another prime opportunity to harvest affection.
The number of people who'd shown up for his birthday was overwhelming. Five years was more than enough time for many to grow—and even Jiraiya, the old perv himself, had returned to the village.
Kakashi was already seven years old.
Which meant the next generation of "cabbages" were ready for harvest.
There was one particularly promising young sprout from the Uchiha clan—Uchiha Obito.
Kaien hadn't even needed to approach him deliberately. By pure chance, he'd been helping Uchiha Fugaku record the clan's internal statistics and stopped by Obito's home.
He handed the kid a lollipop.
And from that moment on, the little guy had been stuck to him like glue.
"Kaien, it's your birthday today! I got you a present..."
----------------
Pls Drop some Power Stones
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