Inside a brightly lit laboratory whose style was completely out of sync with the current era, a middle-aged man with white hair was organizing data on the experiment table.
"Sigh… huff…"
A spark flared as the white-haired man took a long drag of smoke, feeling a slight sting in his lungs before exhaling.
'Failed again...'
The fingers holding the experimental data tightened slightly, crumpling the paper and creating creases.
Just then, the laboratory door opened, and a young figure in a white robe walked in.
His hairstyle was quite distinctive, with both sides shaved, leaving only the middle section tied into a ponytail hanging down his back. He wore multiple earrings, had the number 'IV' tattooed below his eyes, and bore a diamond-shaped black mark on his chin.
The white-haired man turned around, not surprised by the visitor.
He knew very well that the only ones who could enter unimpeded without triggering any alarms, besides himself, were his funding 'partner'.
Well... or maybe 'boss'.
"Amado, how are the experimental results?"
The youth's tone was mechanical and cold, as if lacking much human emotion.
The middle-aged man called Amado, long accustomed to this, simply showed a slightly troubled expression and said to the youth,
"Jigen-sama, all test subjects are dead. Still no suitable 'vessel' has appeared."
Saying this, he opened the laboratory storing the failed experiments one by one, indicating he wasn't lying.
The one named Jigen, who was actually another noble Otsutsuki lineage, only frowned slightly at this.
"Increase the experimental samples. I need you to accelerate the progress."
"Jigen-sama, it's not as easy as you think. I..."
Amado wanted to explain further, but was ruthlessly interrupted by Jigen.
"Don't speak meaningless words. Time is precious to us. I can only give you three more months at most."
Although Jigen showed no emotion, Amado could sense the urgency from his command.
What kind of person could make this Otsutsuki from a thousand years ago so nervous?
Amado couldn't help but recall a certain rumor he had gathered before.
A Konoha's Ninja, with the help of a Jinchuriki, defeated the legendary [Progenitor of Chakra], the 'god called Otsutsuki'...
For one of the few scientific minds in the Ninja World, such rumors were just nonsense until confirmed.
—Until he also encountered someone claiming to be 'Otsutsuki'.
The man before him.
He had shown Amado unparalleled power and promised that as long as Amado helped him obtain the [God Tree Fruit], he would grant any wish… including resurrecting his long-deceased daughter.
And Amado, disheartened by the repeated failures of his own 'clone resurrection' plan, agreed to join his side without much thought.
He didn't belong to any Great Ninja Village or faction, so he had no reservations whatsoever.
Even if he had sensed from Jigen that the man's goal might bring disaster to the Ninja World, he didn't care.
Akebi, as long as you can return to this world, your father will do anything!
Even if it means making a deal with a demon.
Amado was that kind of person.
To resurrect his daughter, he was willing to bear any sin.
As a human, he disregarded others' lives, conducted experiments on humans, and didn't hesitate to cooperate with someone who might destroy the world.
Such behavior could easily earn him the title of the Ninja World's greatest 'human traitor'.
But as a father, his desire to save his daughter and bring her back from the afterlife was not so hard to understand.
To him, his daughter Akebi was everything, the meaning of his existence. For her, he was willing to become an accomplice in the world's destruction.
"Three months... that's a bit..."
Hearing the deadline Jigen had set, Amado couldn't help but break out in a cold sweat.
According to the requirements, the probability of cultivating a suitable 'vessel' capable of containing Jigen was minuscule… it could only be done through sheer numbers.
Compressing the expected timeline from over a decade to three months meant the number of experimental subjects would have to increase exponentially.
This wasn't a small matter like a few missing persons.
It was thousands, even tens of thousands!
He didn't doubt Jigen's ability to capture people, but such a large-scale disappearance would surely attract the attention of neighboring great nations. If they were alerted...
Amado didn't care whether Jigen achieved his goal… he just didn't want his daughter's chance of resurrection to be wasted like this.
At the same time, he became somewhat curious… what exactly was making this distinguished lord so impatient?
Amado didn't know, and Jigen... or rather, Otsutsuki Isshiki, wouldn't tell him.
Ever since he was betrayed by Kaguya a thousand years ago, causing most of his body to be devoured and turned into the God Tree, he had been residing within this monk's body.
However, Jigen's body was an unqualified 'vessel'. He had to find another sufficiently strong, sufficiently talented body to transfer his Kama and thus host his reincarnation.
Originally, after lying dormant for a millennium, Isshiki wasn't so impatient.
Although he had been hiding within Jigen, he was aware of the events unfolding in the Ninja World.
He didn't care about the petty squabbles between Ninja. What truly made him hesitate to act was the moon hanging high in the sky.
Or, more precisely, Otsutsuki Kaguya.
Though unwilling to admit it, Kaguya, having consumed the God Tree Fruit, was indeed stronger than him.
Even knowing she was sealed, Isshiki didn't plan to act rashly.
After all, as long as Kaguya existed, she was a ticking time bomb. He had to wait until he was strong enough before revealing himself.
Having been burned once, Isshiki wouldn't be so easily fooled again.
—Originally, that was his plan.
And it played out as he thought. Kaguya was released by her descendants. Sensing her powerful aura, he once again retreated into his shell, not daring to act.
But what happened next exceeded his expectations.
That Kaguya... had disappeared!
Not even a trace of her aura remained.
Once bitten, twice shy. Isshiki didn't act immediately, choosing instead to continue lying low.
A few more years passed before he dared to reappear.
However, while the enemy was indeed gone, the problems he faced had also emerged.
First, his current body was nearing its limit, lasting at most another ten-plus years… which for the Otsutsuki Clan was like a nap. He had to transfer his Kama to a suitable 'vessel' quickly.
Second... was how to complete the God Tree Plan again.
In some space within an Otsutsuki ruin, he had hidden another spare God Tree's seed… the Ten-Tails.
Even Kaguya didn't know about this.
His original idea was to, after fully reviving, find a way to defeat Kaguya and feed her to his hidden Ten-Tails as fertilizer, thus nurturing another God Tree.
But Kaguya's disappearance left him in a bind... He couldn't just conjure another Otsutsuki out of thin air, could he?
Or wait for Momoshiki and his servant Kinshiki to arrive?
No, no, he didn't want to share the fruit with that guy Momoshiki.
Finally, he set his sights on the aggregates formed from Kaguya's Chakra.
—That is, the Tailed Beasts we all know.
In the past few years, using Jigen's body and his Otsutsuki abilities, he had easily dealt with the lone Six-Tails' Jinchuriki, Utakata, and quietly abducted the Five-Tails' Jinchuriki, Han, from Iwagakure.
Yes, this is precisely why Naruto and his group, as well as Obito, could never find these two Jinchuriki.
Obito's time travel occurred before this event… or rather, it was because the past Naruto brought Kaguya back to the 'present' that the desperate Isshiki began targeting the Tailed Beasts.
This cycle of cause and effect is truly hard to unravel.