Rei was in his room, a massive amount of books surrounding him, but there was a large page on his wall that had seemed to have been enlarged, it was the Impure World Reincarnation jutsu after some convincing, Rei had got Tobirama to give it to him in one instance, purely because Rei believed he could instead of using the souls of the dead, using his own energy to create 'Psuedo-Bodies.' or clones.
He was right, but the process was what would take a while to perfect, as it was now it would take up to six months to properly have a single 'Clone' work. It wasn't simple at all, and in fact, was difficult, and the only reason Rei really got ahold of it was that he had thought to do so, most ninja wouldn't care about the sacrifice to bring back near-immortal and infinite warriors, it took no chakra to keep them up either. Many people wouldn't mind using a few villages purely to have an infinite amount of cannon fodder.
The only thing Rei really found out that is, if you wanted to place yourself into this technique, to attempt to live 'forever.' you would lose the near-infinite chakra and near-immortal body.
Guess this would solve Orochimaru's immortality kink for now so he didn't need to worry about that, and whereas he wasn't as 'Sciency' as Orochimaru, he could still help. Using a mix of his own experience and knowledge, while also helping by using his evolution skills to master certain things normal people couldn't.
When he took it to Tobirama however, he was told to keep it a secret, this kind of thing was far too powerful to just let anyone get ahold of, and whereas Rei already had a few 'Clones' cooking, everything else was burned. The only other person made aware of was Orochimaru, but he would be watched under a very, very intense set of eyes at all times, just to make sure.
This jutsu became called the 'Pure World Reincarnation.' only to the three people who knew it. Rei planned to use it to make his own force, Orochimaru used it purely so he could be 'Immortal' and learn all he could, and Tobirama? The motherfucker used it to make someone do his paperwork for him, even while he was actively participating in the war.
Well, after seeing exactly how much paperwork Tobirama had, can't blame him.
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Rei was currently jumping through the trees, in Anbu uniform and an 'Oni' mask on his face, the squad leader being Fox, and the two others being Crow and Dog. They were currently on a simple information gathering run, infiltrate an enemy camp, get any information, then leave. It was a simple grab-and-go mission.
Fox, the one in the front spoke. "Dog, how much further?"
"Another three minutes and we should arrive near the outer perimeter."
"Good, Oni, you and Crow will enter since you're our best sensors. We will wait outside camp awaiting you, no mistakes. Grab what information you deem important, that's all."
'Oni' and Crow looked at each other before they raised matching hand signs, then they began to go through multiple hand signs before stopping on different ones. Oni clicked his tongue, getting a chuckle out of Crow before the both of them split from the group, speeding up.
(Imagine Anbu rock paper scissors XD)
Soon, Rei was landing onto a tree, watching over the village, Crow was going to infiltrate from the less guarded side, it was Rei's job to infiltrate from the front, which wasn't hard for Rei being as that is what his family focused on, no it was just annoying because Crow would get all the juicy information, and Rei would be left with the scraps.
Suppressing his chakra with both his own skill and seals while also having his seals activated to make him less noticeable, he jumped down and began to sneak his way in, entering tent after tent, occasionally stealing some loose change and money just lying around.
What? Just because he's wealthy doesn't mean he's just going to leave these Ryo's all alone, wouldn't they feel better along with his own Ryo? The more the merrier.
Occasionally he would find a jutsu that he either 1, didn't know, or 2 knew the library he had access to didn't have and he would take it in as well, the subtle uses of his storage seal were easy.
Rei finally got to a rather large tent, entering in he saw a table laid out with what looked like to be frontline orders on their next attack. Rei took a moment to memorize everything, copying the finer details onto an empty scroll he had.
Before he left he found an updated Bingo book, taking that for his own he left the camp quickly, just as a Jonin entered the tent with what looked to be a commander badge.
Soon he was back in the trees with the rest of his squad, all of them looked to each other before they began to mimic a seal, a basic term for 'Ready'.
Once they all made it Fox began to move again, causing the rest of them to move as well.
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With Tobirama, just days before Rei had been assigned into an Anbu squad.
"You want, an Oni mask? What about the animal mask?"
Rei shrugged his shoulders. ''No offense Sensei, but as of now the Anbu are newly formed and are the 'Elite' but if we make out masks all animals, eventually someone will notice a pattern. Because no matter how secretive I might try to be, something will happen, and they will be spotted. The land of the Stone has a similar force as well, and they use masks as well, but if we were to use the masks of other people's squads, then if we were to get 'Caught' we could feign ignorance of being a Konoha Anbu.''
Tobirama nodded softly before he spoke. ''Fine, I understand what you mean so I'll allow it, but this means we need to find out the mask that other nations use, just in case."
"Also make it so Anbu doesn't have anything that resembles Konoha, the mask already hides the use of Dojutsu's, but if the cloaks we use to move the wrong way and they get a flash of our mark, or a clan symbol, it'll just ruin it.''
Tobirama didn't need to think too much about that, simply nodding. He had already planned to make some uniform changes, he's just been so focused on the war and trying to one-up the other nations that it had been pushed off. Rei mentioning it only put it higher up on his list.
''Rei, I have a question for you, would you be willing to share your stealth seals?''
''Some of them yes, if it's for the better of the village then yes.''
Tobirama gave a nod before he spoke. ''Thank you."
Rei joined his hands together and bowed before leaving. Right before he left however he spoke. ''Though, to confirm. I do have a way to see through my own seals, only I know it. It isn't anything personal, you understand.''
Tobirama did in fact understand, even if he could consider Rei a 'Pal.' not even Tobirama would let Rei know everything in his arsenal. Share your strength, but never share the weakness. They are ninja, not some honor-bound samurai or devoted knights.
(Pa-treon.)