Many of Konoha's most infamous forbidden jutsu were the brainchildren of Senju Tobirama. And while Tobirama's reputation wasn't exactly sparkling, Orochimaru, a man with no moral purism to speak of, deeply admired him.
After all, Tobirama's methods, however questionable, had undeniably made Konoha strong.
But just having Shirou's body wasn't enough. Orochimaru still needed the Impure World Reincarnation jutsu. He secretly infiltrated the vault where the forbidden jutsu scrolls were stored, but to his dismay, it wasn't there.
He did, however, find an immortality jutsu that was even more to his liking. Unfortunately, the learning curve was steep. The jutsu involved the soul, a field Orochimaru had never paid much attention to. It was a whole new discipline, and even he, a self-proclaimed master of all jutsu, felt a bit strained.
Fortunately, Tsunade was still traveling. Orochimaru believed he had plenty of time. If he was right, the Impure World Reincarnation scroll was still in the Scroll of Seals, managed by the Hokage himself. He just had to find a way to get to it.
Meanwhile, the situation in Konoha was growing grim. Victory in the Second Great Ninja War had come at a heavy cost. They were even sending fresh-faced academy graduates to the front lines. In a desperate bid to bolster their strength, the higher-ups, much like their teacher Tobirama before them, began to dabble in the forbidden.
For example, the cells of the First Hokage, Senju Hashirama.
In a routine meeting, Danzo Shimura proposed they use human experiments to restore the First Hokage's Wood Style.
"This is a desecration of Lord First's memory," Hiruzen said, his face etched with worry. As the Third Hokage, he was growing older, and the weight of his responsibility felt heavier each day. He was torn between the feelings of his people and the very real threats from the outside world.
"Hiruzen," Danzo said, his face already wrapped in bandages, "hasn't this war made you see clearly? This isn't the end. The next war could come sooner than we think. To protect Konoha, we should spare no cost. We must find a way to regain Lord First's power. We just have to keep the experiments completely confidential."
"Then let Danzo be in charge of it," Koharu Utatane, a Hokage advisor, agreed.
"This experiment must be kept strictly secret," Homura Mitokado, another advisor, added, offering no objection.
"But," Hiruzen relented, but laid down his one condition, "if a major problem occurs, the experiments must be stopped immediately!"
"Human experiments are never absolutely safe," Danzo said, casually treating human lives as a necessary cost.
He then pivoted. "If we could obtain some of that Lord's knowledge, it might reduce the casualties. After all, he is the greatest medical ninja, the first to use human surgery for treatment."
"That Lord's soul has long since ascended," Hiruzen said, completely shutting him down.
"Actually, I did hear some news," Danzo said, glancing at Hiruzen. He didn't believe for a second his old friend hadn't noticed. "I heard Tsunade brought back a crystal coffin from Shikkotsu Forest."
The matter hadn't escaped Danzo's notice. At the time, Tsunade's status and the close watch on her made it too risky to act. Now, with her out of the village, he believed the time was right.
They had Shirou's body; the only problem was that no one in Konoha had mastered the Impure World Reincarnation.
Danzo had already taken the scroll from the secret room, which was why Orochimaru hadn't found it. But actually learning the jutsu was another matter entirely. The fact was, he knew the real key wasn't the one being resurrected, but the user.
Danzo just needed someone who could perform the jutsu. And who was more likely to learn it than the "Professor" himself, the Third Hokage?
As for what happened after... well, Danzo had plenty of ideas on how to use Shirou. He'd spent ten years traveling with the man; he knew his kindness. It would be child's play to manipulate him for Konoha's benefit. He even thought he could do it better than his teacher, Tobirama.
But Hiruzen refused, his voice sharp. "We will absolutely not use the Lord again!"
He remembered the conflict with their old companion, Torifu, and the shame it had brought upon Konoha.
To say something that shouldn't be said...
How dare Danzo bring up the old matter again!
Hiruzen knew the weight of that office, the years he'd spent trying to restore Konoha's reputation after Tobirama's reign. He wasn't about to go through that again.
The generation that had lived through the first war wasn't dead yet! If word got out that Konoha was using Shirou again... could he even imagine the fallout?
"Hiruzen, you should also know," Danzo pressed, his eyes fixed on his old friend, "if we can use him again, it means more of our people will survive in the future."
"Danzo!" Hiruzen roared, furious. "Do you want the next generation to feel, like Torifu did, that it's better to die than to live in humiliation!"
Torifu's accusation still rang in his ears.
As Hokage, Hiruzen had come to understand the immense value of a good reputation. It brought missions in peacetime and allies in wartime—something money and power couldn't always buy.
"No one in Konoha is allowed to practice the Impure World Reincarnation jutsu! This is a ban from the Hokage! Anyone who violates it will be severely punished!" He stared daggers at Danzo, trying to drill the point home. "And absolutely no one is allowed to touch the crystal coffin in the medical secret room!"
Danzo's face turned exceptionally ugly. He'd never been so humiliated. He just grabbed his sword and stormed out. "Hiruzen, you will regret this."
"Danzo, I am the Hokage!" Hiruzen shouted at his back. "Any Konoha ninja must abide by the Hokage's ban! Violators will be severely punished, and that includes my advisors!"
Bang! Danzo slammed the door shut.
The two remaining advisors exchanged uneasy glances. On one hand, Shirou's influence was waning. On the other, Danzo's proposal had its merits.
After leaving the office, Danzo glanced back coldly.
It was a pity.
Hiruzen was the most likely to learn the jutsu. Then he remembered that other young man, the one so interested in all jutsu.
If the Hokage's disciple used the jutsu... well, that couldn't be blamed on him, could it?
And conveniently, Danzo had the scroll, and Orochimaru had the coffin. All they had to do was wait for Orochimaru to learn the jutsu.
And so, they colluded. When Hiruzen ordered the Hashirama cell experiments stopped due to the high death toll, Danzo and Orochimaru continued them in secret. But the main prize was still the Impure World Reincarnation.
"What a pity," Orochimaru once mused, fascinated by Danzo's obsession. "I've never even met that Lord."
As Danzo grew older, his views became more extreme. His evaluation of Shirou was reduced to a single, cold sentence: "Just a very easy person to use."
Of course, other people in Konoha would not think so.
-----
In a certain small household, a little boy who was growing up asked his father about the bedtime stories he heard every night.
"Did such a perfect person really exist in the world?"
"Of course, he existed," Sakumo Hatake said, a faint smile playing on his lips. "Let me tell you a secret. I have personally seen such a perfect person!"
"Dad's lying again," little Kakashi said, pulling the covers up to his chin. "I'm not a two-year-old. That's a person who's been dead for over a thousand years."
"Hahahaha," Sakumo patted his head. "Dad's going out for a bit, maybe..."
"Are you going on a mission? I can take care of myself!"
"I'll be back as soon as I can," Sakumo said, turning off the light. A flash of watery light appeared at his fingertip—Storm Release—illuminating his path out of the dark room.
Little Kakashi peeked out from under the covers. He already knew it was the Storm Release kekkei genkai. One day, he'd awaken that power, too.
But he never would have thought that this mission would be a path full of thorns, one that would cause a dramatic, terrible change in his already half-empty, warm family.