So Danzo already wants the Sharingan at this point in time...
Arata was not surprised.
Honestly, it made perfect sense.
In the past, Konoha's jinchuriki had all come from the Uzumaki clan. The problem was that Uzushiogakure had been destroyed by war many years ago. After that, Konoha picked back up on Hashirama Senju's old research into suppressing tailed beasts, which led to the Wood Style experiments.
Because the survival rate in those experiments was catastrophically low, with Yamato as the only survivor, they had been forced to shut the project down.
Under normal circumstances, with the Fourth Hokage around, a master of sealing jutsu without equal, Konoha should not have needed to pursue research into Wood Style or controlling the Nine-Tails through the Sharingan.
But the Fourth Hokage had died during the Nine-Tails' attack.
The village was weak. Wars kept breaking out. The jinchuriki was just a child. Under those conditions, Konoha had little choice but to quietly restart its research into how to control the Nine-Tails.
If the Third Hokage had not held the line, Naruto would never have had anything resembling a peaceful childhood. More likely, he would have ended up in the same situation as Gaara next door.
The real reason Konoha's hardliners, Root, or more specifically Danzo, had been tolerated by the village leadership was that the old bastard had taken responsibility for figuring out how to control the Nine-Tails.
Orochimaru's involvement with Root probably had something to do with that too.
Later on, Danzo even risked being consumed by Hashirama's cells by transplanting that arm into himself. That was the real reason he could orchestrate the Uchiha massacre, stockpile so many Sharingan, and ultimately get away with nothing worse than Root being officially dissolved, only to reemerge after the Third Hokage's death.
Still, on the current timeline, the Third Hokage would most likely never approve any plan involving the Sharingan and the Nine-Tails.
Even as Arata made that calculation, he still felt a flicker of urgency.
Just as he was experimenting with controlling Sasuke, he did not completely trust the manga's plot. If reality differed from the story even a little, that discrepancy might be enough to get him killed.
Old man... old man. Let's see whether you can hold the line a little longer.
He looked at the Third Hokage, still standing there with a troubled face as he stared down at the village streets, thought that to himself, and then hurriedly left.
If he spent even a little too long outside, his chakra would start dissipating.
That was the sort of thing that could get him killed.
---
One day later, that afternoon, in a forest training ground.
Whoosh! Whoosh! Whoosh!
Sasuke hurled kunai through the air, flipped forward, and landed cleanly on a rock.
Eight kunai, thrown from both hands, all struck perfectly inside the red circles painted on the tree trunks.
"Hah..." He let out a breath and walked forward to collect them.
For some reason, he had the strange feeling that over the last two days, along with the nightmares, his chakra reserves, his weapons accuracy, and even his observational ability had all been improving at a startling pace.
If my brother knew...
Sasuke froze in place, his emotions tangled.
The bloodbath in the dream felt horrifyingly real. If, inside the dream, he ran home as fast as he could, he could even see his parents murdered by his brother's own hand and hear the strange words his father spoke before dying. If he ignored all of that, he could still find the report card from his first term at the Ninja Academy inside the house.
In the illusion, his mother had carefully stored it away in a box.
The unbearable realism of the dream kept dragging his thoughts in darker and darker directions.
"Haaah..." Drowsiness came over him again.
Sasuke knew he was about to fall asleep once more. By now, habit had taken over. He did not resist. He simply sat down against the rock, closed his eyes, and his breathing quickly deepened and slowed.
The next second, he opened his eyes, checked where he was, and vanished from the spot.
Arata controlled Sasuke's body as it moved through the woods for a while, then arrived at a lakeshore not far away. He formed hand seals with both hands, started with the basic academy jutsus, then immediately followed with another string of seals and blew toward the lake.
"Whoosh!"
Flames roared outward.
The Fire Style: Great Fireball Jutsu, which Sasuke himself had not even learned yet, came out smooth and practiced.
Good. Even his chakra is fully under my control now, Arata thought with a satisfied nod.
That extra little nod, the unnecessary tiny gestures and expressions, were things he had deliberately begun imitating in order to get used to controlling a human body as naturally as possible. If he ever truly needed to fight or speak while wearing Sasuke's body, any stiff or incomplete movement might expose him.
He needed to seem more human.
If he were discovered, he could already imagine the outcome: captured, sealed away.
The tailed beasts, his closest equivalent in this world, had not exactly enjoyed happy endings.
After briefly testing his complete control over Sasuke's chakra, Arata focused and moved on to the final step.
His own chakra fluctuation became markedly stronger. Great patches of black curse-like markings spread across Sasuke's skin, only to sink away again a moment later.
Excellent. The body adapted very well. Even the summoning contract worked...
Arata did not let the surge of satisfaction interfere with what he needed to do next. Silently, he guided Sasuke's body back to the clan district as fast as possible, picked an Uchiha clansman from the hardline faction who happened to be home, slipped his chakra body inside, and released a wave of genjutsu. Once the man was under control, Arata returned to Sasuke's body to stabilize his chakra, then went back in and began analyzing the unconscious Uchiha's neural signals.
His plan had never been to control Sasuke alone and somehow turn the whole situation around.
That would have been far too complicated. The Uchiha rebellion and massacre had never been caused by a single issue. They were the end result of multiple conflicts and overlapping interests grinding together.
Much easier to simply control everyone.
After all, as long as Shisui and Itachi did not stray too far from the original plot, they were not going to massacre Uchiha who had no intention of staging a revolt.
Obito's position was still unknown.
Danzo, on the other hand, might be troublesome.
But not unmanageably so.
Arata did not linger long. After analyzing the signals for a while, he decisively withdrew. A single cast of genjutsu would not maintain itself for very long without him remaining inside to interfere, and he had no intention of continuing to use the Night of the Massacre or any other complicated template. He had used that on Sasuke only because time was short and he needed control quickly. For the other nobodies, it would be enough for the genjutsu to simulate whatever they were already doing in real life.
Even if that meant it would take more repetitions to fully control them, it did not matter.
What he wanted was to avoid being noticed.
Not everyone had an Itachi watching over them, or contact with Shisui. Even if ordinary Uchiha awakened the Sharingan, they were not going to activate it for no reason just to inspect the chakra inside another clansman's body. As long as he avoided acting on the days of the clan's secret meetings, that was enough.
If only the body I could inhabit without limits wasn't Sasuke's...
With that regretful thought, Arata went on to visit the homes of several more hardline Uchiha ninja in succession, giving each of them their first taste of his genjutsu. Afterward, he swiftly returned with Sasuke's body to the forest, found the original spot where Sasuke had fallen asleep leaning against the rock, sat back down, and slowly released control.
From today onward, there would be no need to keep using the Night of the Massacre illusion on Sasuke.
From here on, it would be enough to simulate ordinary life and training inside the genjutsu. His body and chakra were already completely under Arata's control anyway. So long as the gap between the illusion and reality did not grow large enough to make Sasuke notice something was wrong, it did not really matter how different the things he did or saw were from what was actually happening.
"Hypnotizing the Uchiha. Step one... complete."