The fact that there was no rejection after fusing with Hashirama's cells meant that this descendant of the Uchiha—Uchiha Jiuyu—now had the qualifications to serve as his pawn, to carry on the grand plan he had laid out even after his death... Of course, that was provided Jiuyu could pass the trials that followed.
To survive without succumbing to cellular rejection showed that this Uchiha possessed considerable potential.
But whether that potential could truly be transformed into strength was still uncertain. Over the years, Jiuyu was not the first promising Uchiha to fall into this underground base. Yet, all of his predecessors had failed to pass the subsequent trials.
They could not convert potential into power.
And in the end, not only did they die, but the decrepit old man himself—unable to entrust his ambitions to anyone—had been forced to linger on, clinging to life through the power of the Demonic Statue of the Outer Path.
He could only bide his time, desperately awaiting the arrival of a successor capable of shouldering his plan, someone who could let him finally die in peace, even if only for a while.
"Take this brat below. First, reattach his broken limbs. Hisashi… Since you were the one who brought him back, you'll be the one to look after him from now on."
The old man seated on the stone chair turned his gaze toward the White Zetsu.
There were many White Zetsu.
Most lacked significant combat power, their abilities useful only for espionage and stealth. But a small number carried the latent power of Hashirama's cells, having inherited his Wood Release. These rare individuals were so formidable that they could match or surpass many elite jōnin.
This small group not only differed in appearance from ordinary White Zetsu, but he had also given them individual names for easy distinction.
The one before him was one such exception, bearing the name Hisashi.
"You want me to look after a kid? I don't have any experience with that!"
Hisashi grumbled at the command.
Like all White Zetsu, his body had no gender, his skin pallid and rubbery like gelatin. But his face was peculiar—shaped like a peach, or perhaps more crudely, like a buttocks, with only a single eye rolling about in the cleft.
"As for gathering information on Jiuyu, that will be Black Zetsu's task, not yours."
"Then maybe looking after the kid should be handed to—"
"Hisashi. You will look after him. That is an order."
"…Fine! Let's hope this brat doesn't give me too much trouble."
Hisashi's peach-like face twisted into an oddly comical look of resignation. Though strange, it was genuine. The old man, though ancient and decrepit, was still of Uchiha blood. His vision was sharp—so sharp he could count the legs of an insect crawling on the wall.
He saw Hisashi's expression but did not rebuke him. Instead, he continued, "Keep an eye on him. And don't forget to tell him—no, Black Zetsu will explain what must be done, and how. For now, take him below for limb grafting."
Uchiha Jiuyu lay on the ground, missing his left arm, both legs shattered nearly beyond repair.
By all logic, such wounds meant that—even if he lived—he should be doomed to a lifetime confined to bed.
And yet, here, such logic could be overturned.
Limb transplantation was no great obstacle. As long as a spark of life remained, even ruined internal organs could be replaced with those cultivated from Hashirama's cells. Sadly, even Hashirama's power could not halt the erosion of time.
"Yes, Madara-sama."
Hisashi hefted the unconscious Jiuyu onto his shoulder and withdrew.
Seated on the stone chair was none other than Uchiha Madara himself—the man said to have fallen at the hands of the First Hokage at the Valley of the End. The old man who had clung to life long past his time lowered his heavy eyelids, pondering whether Jiuyu could truly pass the trials, and thus grant him the peace of death, even temporarily.
Until—
A cold, familiar voice slithered into the chamber.
The ominous form of the yin-yang, pitcher-plant-faced creature appeared beside the old man.
"Madara-sama."
"You already know, don't you?"
"Hisashi has told me. I also saw the boy myself. His potential looks promising. Once his mind is reshaped… our plan can truly begin."
"Then I leave that to you."
"Yes."
A grim smile curved across half of Black Zetsu's face. "I will see it done."
The old man said no more.
He trusted Black Zetsu absolutely. After all, Black Zetsu was a creation born of his Rinnegan—an extension of his own will, incapable of betrayal. To betray him would be to betray oneself.
And in all the years since its creation, Black Zetsu's actions had never once given him cause for doubt.
As the old man closed his eyes, sinking into apparent slumber, Black Zetsu slipped away, silent as a fish through water, gliding effortlessly through the underground complex until he reached what resembled a library.
Shelves lined the room, stacked with scrolls and files.
These were intelligence records.
Information gathered by White Zetsu operatives scattered throughout the shinobi world.
"Let's see… Uchiha Jiuyu's file…"
The pitcher-plant creature drifted before a shelf, scanning the spines.
Even a being like Black Zetsu—strange, near-immortal—could not store everything in memory. His mind, already burdened with centuries of knowledge, would dull if he retained too much. Thus, he deliberately forgot certain things, while committing others to memory.
What he did not carry in his mind, he stored here, catalogued in this archive.
Candidates like Uchiha Jiuyu were noted only in broad strokes—until they were chosen by Madara's eye. Only then would he retrieve their full dossiers.
"…Found it."
From among the files, he drew one labeled with Uchiha Jiuyu's name. Opening it, he scanned the pages: records of birth, family background, past experiences—all laid out in detail.
It did not cover every moment of Jiuyu's life, but the outline was clear.
"…Both parents killed in battle… raised alongside his younger brother… how perfect!!!"
Reading those words in stark black ink, Black Zetsu's face twisted into a smile brimming with malice.