From the death of the Fourth Hokage up to the era of Pain, the ninja world had long suffered a shortage of "top-tier combatants," a gap between generations.
The era of towering titans had not yet arrived. The tattoo era was still a distant dream. In this transitional age, a bunch of so-called ninja clan descendants dabbling in their respective "secret techniques" were already regarded as powerhouses.
Add in a bit of scientific research and some basic study of Tailed Beast chakra, and that was essentially the measure of this era's strongest.
However, lurking in the shadows were monsters, entities that possessed the power to obliterate everything.
Aside from the Sages from the Three Great Sage Regions, there was the Sage of Six Paths in the Pure Land.
And the sealed Kaguya Ōtsutsuki on the moon.
But the last of them… was the seemingly ordinary monk Yoru had locked eyes with before—the one with the edgy "visual kei" look.
Jigen.
Or more accurately—
Ōtsutsuki Isshiki.
This eccentric-looking monk, revered by the monks of the Fire Temple, had in fact been wandering this world for over a thousand years. He was the true leader behind the Kara organization, and had once descended to Earth alongside Kaguya Ōtsutsuki as a member of the Ōtsutsuki Clan.
He was the very same being whom Yoru had seen in the underground lava under the Land of Hot Springs, through the corrupted memories of the evil god Jashin—a being who wiped out countless Earth natives with a mere wave of his hand.
Thousands of years ago, in the ancient past, Isshiki had come to Earth with his guardian Kaguya Ōtsutsuki to plant the God Tree and raise the Ten-Tails, cultivating it to produce a chakra fruit.
After clearing the planet of the native population, Isshiki intended, as planned, to sacrifice the lower-ranked Kaguya to the Ten-Tails.
But just as he was about to carry it out, Kaguya turned on him, launching a surprise attack.
Caught completely off guard, Isshiki suffered near-fatal wounds. In desperation, he used his dōjutsu to parasitize a passing young monk—the one now known as Jigen.
Under normal circumstances, even without consuming a chakra fruit, an Ōtsutsuki's base power level is Six Paths-tier—a fundamental difference in lifeform tier.
Isshiki, a noble, a protected one, and a high-ranking figure within the Ōtsutsuki clan, had certainly consumed chakra fruit before — just not the high-quality fruit produced on Earth.
Whether in the memories Yoru inherited from the Evil God Jashin, or in canon where he fought Naruto and Sasuke even while heavily weakened — Isshiki's strength was displayed vividly.
Even now, despite still being in a parasitic state and carrying grievous injuries from Kaguya's betrayal, his power far exceeded what the current ninja world could bear.
If pushed too far… not even Yoru could claim to win.
If the clam and the mussel fight, the fisherman profits—should he and Isshiki clash, that old bastard in the Pure Land would never just sit by and watch.
"You three stay here. I'll go take care of something."
Yoru left a brief instruction before his figure vanished.
Terumi Mei and Pakura exchanged a glance. Without hesitation, they grabbed a still-dazed Hikari and returned to their temporary lodging.
Once there, Mei pulled out a scroll and retrieved several azure crystals, placing them in the corners of the room.
"Is all this precaution really necessary?" Pakura asked quietly. "With that guy's power, who in this world could pose a threat to him?"
"There is someone."
Mei shook her head. For the first time, her beautiful eyes were filled with grim seriousness.
Just from the look on Yoru's face earlier, she already had a strong guess about the monk's identity.
If she was right, then that monk… was likely the very entity Yoru had long regarded as his ultimate opponent, the greatest hidden danger in the ninja world—one of those chakra-devouring dominators wandering through the universe.
An Ōtsutsuki.
...
The air shimmered as space warped. Yoru appeared silently just outside the Fire Temple.
The breeze stirred the forest leaves. As if expecting Yoru's arrival, Jigen—or rather, Isshiki—stood calmly, making no attempt to leave.
Sensing the twisted space behind him, his eyes narrowed slightly. He glanced back, then turned away again.
"So you did notice," Yoru said calmly. "Normally I wouldn't have been able to find you—but I've seen you with my own eyes."
He followed Jigen's gaze toward the grand Fire Temple ahead.
"Through the memories of Jashin, hidden beneath the Land of Hot Springs, I saw your purpose and power. Never thought I'd actually meet you, a thousand years later… in a form like this."
"The Land of Hot Springs…" Jigen furrowed his brows, as if searching ancient memories. After a moment, a flicker of disdain crossed his face.
"That lowly creature managed to survive, huh."
"And your current state isn't that much better than his," Yoru shot back with a smirk.
"Taunts won't work on me."
Jigen's eyes were calm, like a thousand-year-old well, undisturbed.
He had experienced a thousand years in this world. The betrayal a thousand years ago had caused him to lose most of the information he had accumulated by constantly devouring chakra fruits.
This meant that for a long time, he was unable to accumulate enough chakra to activate the complete 'Karma' to achieve his reincarnation and revival.
But those thousand years had taught him much:
How to scheme.
How to endure.
He had existed within Jigen's body for countless years, witnessing all of shinobi history. He had the patience and the confidence to wait for his era to come again.
A few sharp words? They meant nothing to someone who had refined his will over a millennium.
"I can feel that special power on you, and I can also see the path you are walking. It is completely different from the Ōtsutsuki clan, yet also incredibly similar."
Jigen looked at Yuki Yoru: "The descendant of that traitor won't allow you to continue on this path."
"And what about you, the one who tried to sacrifice his own 'mother'? Think he'll spare you?" Yoru sneered.
"I prefer talking to smart people, Ōtsutsuki. And you seem like one."
"...What do you want?"
Their power gap was clear, but if Isshiki fully unfroze his Karma, the situation could flip in an instant.
Yet doing so would put a ticking clock on his remaining lifespan—a price Isshiki refused to pay.
Negotiation was acceptable.
The past thousand years had taught him that the Ōtsutsuki's arrogance would only lead to ruin if left unchecked.
And this man—this spirit-wielding Yuki Yoru—was not a mere mortal. In many ways, he stood on equal footing.
"I want intel on the Ōtsutsuki Clan," Yoru said flatly. His gaze lingered momentarily on Jigen's hand.
"You came to the Fire Temple for that boy's chakra, didn't you?
No—more accurately, you came to see if the kid with all that Nine-Tails chakra could become your next vessel."
"You…!"
Isshiki raised an eyebrow in surprise.
"You don't even carry a drop of Ōtsutsuki blood, yet you know all this?!"
"And after a thousand years, all you've achieved is possessing this frail body?"
"You sharp-tongued little—!"
Despite the exchange of barbs, neither moved to attack.
They both knew: if they fought, someone else would benefit. And they both despised that third party lurking in the Pure Land.
"If you can help me cultivate a vessel strong enough to bear my Karma," Isshiki declared, head held high,
"Then I'll give you all the information you want—including the secret behind my thousand-year longevity!"
"Useless," Yoru scoffed.
"Eternal life is nothing but the lowest pursuit. Longevity means nothing to me."
"Arrogant…"
Isshiki grunted, but didn't argue.
At their level, life itself had long lost meaning. Whether it was the digital immortality of the Ōtsutsuki or Yoru's own spiritual essence—they had both long transcended the concepts of flesh and mortality.
"What do you want, then?"
"The method to cultivate the Ten-Tails."
"You… you're after this world's power too?!"
Isshiki narrowed his eyes, scanning Yoru up and down before sneering.
"Only Ōtsutsuki blood can awaken the Ten-Tails. Even if you had it, it's useless to you—wait…
Don't tell me you plan to—?!"
"Interesting. For a so-called Soul Master, that's quite the ambition.
Aren't you afraid your subordinates will betray you?"
"Betrayal is irrelevant, because loyalty never existed in the first place."
Yoru's tone was calm and indifferent.
Ever since he began spreading Shinigami power in this world, he had never expected those wielding it to be loyal.
His followers—aside from his core base in Kirigakure—had their own motives. The Shinigami of Soul Society only served him out of circumstance.
Just like the Sage of Six Paths once had.
He spread chakra not to earn loyalty—but to grow power, and eventually harvest it.
"Truly ambitious," Isshiki muttered.
Even he, after a millennium of hiding, had to admit—Yoru was a terrifying visionary.
If given enough time to grow, he would become a threat even within the Ōtsutsuki Clan itself.
After a long silence, Isshiki spoke:
"Very well. I'll give you the Ten-Tails cultivation method.
But only if you provide a vessel capable of bearing my Karma."
The Ten Tails was the Ōtsutsuki's key weapon for harvesting chakra across worlds — enabling them to devour planetary life and produce chakra fruit. These fruits extended life, enhanced power, and could even be used in alchemical processes.
However, for the Ten-Tails to truly transform from a 'Tailed Beast' into a 'God Tree' capable of producing chakra fruits, an Ōtsutsuki would be required as a sacrifice.
Of course, if it was based on Yuki Yoru's idea, Yuki Yoru wouldn't directly activate the Ten-Tails. Instead, he would 'modify' it, changing it from the God of Ten Eyes that devours life to condense chakra fruits, into a monster that devours souls, uniquely his own.
But this was no longer important to Jigen. What he cared more about was his path to revival!
His chakra was too powerful, so much so that Jigen's body and his natural energy cultivation couldn't withstand his chakra, making him unsuitable as a 'vessel' for his reincarnation.
If Yuki Yoru could really find a 'vessel' capable of holding his 'Karma' to revive him and return him to his peak state, then what did it matter if he gave Yuki Yoru this little Ten-Tails?
An Isshiki Ōtsutsuki in his full power had the confidence to sweep everything away!
Just as he had swept away the natives when he first arrived on Earth, as long as he could return to his peak, he, Isshiki Ōtsutsuki, could control the entire situation.
Kaguya's descendants, the ruler of souls, the sages of the Sage Regions—to him in his full power, they were all nothing!
"Don't worry," Yoru said as he pulled a brilliant blue crystal from his robes and tossed it to Jigen.
"When I find a worthy vessel, I'll contact you.
Prepare everything in the meantime."
"It's a deal."
Casually taking the crystal, Jigen gave Yuki Yoru a deep look and then conjured a special black rod, tossing it to Yoru.
Then, a dark spatial rift suddenly appeared behind him, swallowing his figure whole.
Yoru took the black rod, feeling the special chakra it contained, his eyes flashing. He lingered in the space where it had disappeared for a moment before his figure also vanished from the spot...
...
Land of Rain, Amegakure.
Hiruko emerged from the operating room, beaming with confidence at the anxious Konan pacing outside.
"Relax. The Leader's condition is excellent.
In fact, this injury helped his body fuse more perfectly with the First Hokage's cells."
"He's stronger than ever."
"He's healed?" Konan exhaled in relief, releasing the paper flower clenched tightly in her hand. She rushed inside without a word, leaving Hiruko to scratch his bandaged jaw awkwardly.
But before he could turn to leave—
"Hiruko! Hiruko! What's happening to Nagato?!"
Konan's voice rang out from the room in panic.
Startled, Hiruko quickly stepped back inside.
The sight that greeted him made even him freeze in place.
Nagato, who had been fully healed, was now sitting cross-legged on the hospital bed. His skin was rosy, his red hair vibrant, his chakra strong.
But his body—
Was being overrun by branches and flesh-like growths, snaking across his form like arms, crawling over every inch of him.