Rei got up early and after checking if Mabui came back home, he made breakfast
{The fridge has been refilled...but she's not here. Did I just miss her?}
Mabui was informed of his month long training at Unraikyō before he left, but because of her mission, it had been quite some time since he saw her. His curiosity to know what kind of task required her to be gone so frequently only grew
"Whatever, it's not like thinking about is going to help. The fact the fridge has been refilled recently means she's okay. I've got my own problems to worry about"
Finishing his breakfast, Rei gathered his belongings and reverse summoned himself back to his lab
"Ugh...hard to breathe. It's amazing how much dust can gather in over month. F*ck it, I can't work like this"
POOF! POOF!
Making two clones to help him, Rei went to work cleaning the up place. After he finished, he took out the black scroll the Third Raikage left him
"..."
[Are you sure you're ready?]
"Only one way to find out"
Rei placed the scroll in front of him and began inserting his chakra into the strange Kanji-like pattern that was sealing it but...
SCREECH!
"Ah?!"
...as if rejecting him, his chakra was repelled and sent back at him in the form a small shockwave
"Jeez, Darui was kidding about the protection, freaked me right the hell out.
Approaching the scroll again, albeit with more caution, he made another attempt
SCREECH!
"Agh! Ow! Damn it...let’s see if this works!"
SCREECH!
"Urgh! Again!"
After multiple failed attempts, Rei folded his arms and contemplated
"Just what am I doing wrong?"
[I still don’t know what you’re doing]
"Haven’t you been paying attention? I’m trying to break this stupid lock"
[By bombarding it with your chakra? Sure...that makes sense]
"I’m sorry, is there an opinion you’d like to share?"
Frustrated over multiple failed attempts, he was in no mood for Notitia’s usual sarcasm
[I'm just saying...closing your eyes, wasting away at your chakra, and hoping you get lucky isn't something I'd expect you of all people to do]
"...What?"
[Unless there's no other option, "winging it" is not really your style]
"..."
[Just think on that when you try again. Or don't, cause watching you get blasted on your ass never gets old]
"Jackass. Shut up and let me work"
After taking in Notitia's words, Rei decided on a different approach. Picking up the scroll, he began flowing his chakra into it when he noticed a strange phenomenon. The seal, which was in the form of a single Kanji letter, seemed to faintly glow white on certain parts of it
{...No way}
SCREECH!
[Failed again huh]
"Yeah, but at least now...I know what to do"
[You do?]
"I think I do. The lock...er...seal, is like a one line puzzle"
Trying once more, the scroll rejected him again
SCREECH!
"Ow!"
{Now I get it...}
[It didn't work again]
"I wouldn't say that"
[What are you talking about? It still rejected you]
"True, but it took longer this time...proving my hypothesis"
[You've lost me]
Rei picked up the scroll and pointed to the pattern seal
"The seal is this weird Kanji that's keeping the scroll from opening. The 'lock' is a one line puzzle. Meaning, one must flow their chakra along the lines of the 'Kanji'/seal in order to unlock it"
[Is that all? That doesn't seem too hard]
"Oh believe me it is. For starters, I can't stop after I started, each individual line requires a different amount of chakra, and if I take the wrong path and overlap one line with another, it causes the reaction we just witnessed"
[...]
"Notitia?"
[The seal seems like it's gonna be bitch and a half to remove]
"I won't argue with that. Still, with great risk comes great reward"
Making another attempt, Rei carefully flowed his chakra along the lines of the seal
"Y-yes! It's working! Just have...to...maintain...this pace!"
Taking the upmost caution, he concentrated with all his might to the point the clones he made earlier disappeared
{Ngh! Wow, this is much harder than I'd though it'd be. Come on, come on, come on!}
Rough breaths, veins appearing on his temple, and a burning sensation on his fingers, Rei struggled with all his might until finally...
WHIZZ!
"?!"
[Well I'll be...]
...the seal somehow moved along the paper as the scroll opened. Positioning itself next to the instructions written down
"Heh. You were right Notitia"
[Right about what?]
"I've been so wrapped up at 'playing ninja', I've forgotten what I really am...what I've always been"
[And that is?]
"A scientist. 'Winging it' is certainly not my style, charging in blind without a real plan, relying only on luck, is more of an idiot's speed. But me...I study, test, prepare, hypothesize. Naruto's opener is a one-two punch combo with a side of clones...my opener is The Scientific Method"
Taking a look at the now opened scroll, he was perplexed as only the image of a human body could be seen with various straight lines pointed on certain parts of the body
[Seriously? No instructions at all? Just a poorly drawn picture?]
"To the naked eye...but like Tango said, 'read between the lines'."
Looking carefully at the diagram before him, an idea came to mind
"Hmm, lets try this"
POOF!
Rei made a clone and handed over the scroll. The clone sat down and formed a hand seal, focusing its chakra on a specific point before wreathing in pain and vanishing
[Using a clone to test it, rather than your own body...smart]
"More like, common sense. Now I know what this scroll is all about thanks to the information my clone gave me"
Because shadow clones transfer all information and experiences of the clone to the user when they disappear, he knew the exact sensations the clone felt before it vanished. Giving him his next clue
[Well...spill. What is this secret technique?]
With a large grin on his face, Rei responded
"It's more of a 'method' rather than a technique but in a nutshell, it's for strengthening the human body. Darui was right, opening this scroll has given me all the answers!"
[Oh?]
"Don't you see? Everything fits! Why the Third was the only one able to withstand moving at the speed of light with nee-san's Space-Time Ninjutsu. How this gave the First the 'strength' to create Kumogakure. Even the creation of Nintaijutsu stems from this. This hidden method enhances everything in the human body!"
[...That's it? A strengthening technique? Kind of underwhelming if that's all it does. Especially if you consider all the other techniques out there that can do the same thing]
"No...this is entirely different. They can't even compare to this"
[How? Take the Raikage for example. Wasn't that crazy strength a result of his Cloak of Lightning?]
"That's only part of it. Besides stimulating the nervous system for better reactions, the cloak increases both strength and defense by relying on high frequency vibrations. Used offensively, the vibrations destroy anything in their path. Defensively, they deflect pretty much all attacks. But they could only withstand using that technique because they strengthened their bodies with this method"
[I always did wonder why only the Raikage used such an awesome technique and not share it with the rest of his ninja. You'd think everyone in Kumo would use it]
"It's not that other ninja wouldn't use it, but rather they couldn't use it. It's also how this method led to creation of Nintaijutsu in the first place. Only an inhuman body could use such inhuman techniques. Well...that's my theory anyway"
[How does this even work anyway?]
"The purpose of the 'lock' wasn't just to keep the contents a secret, but a means of teaching this method by showing you exactly how to manipulate your chakra when you break it. This diagram in the scroll tells you exactly which parts of the body to use it on"
[But it only shows certain parts of the body. Why not just use it on every...wait...your clone!]
"You're starting to get it. This method is a long and dangerous practice. One that must be completed overtime. Darui told me this scroll has four locks on it. This is only part one. Check this out"
FLOOVP!
Rei picked up the scroll and tried to open it further, but the seal reappeared and wouldn't allow him to open it any further
[Is that...]
"Part two. And I've already tried, but my chakra control isn't good enough to get past it yet. Which is why I'm glad this seal is here. If anyone without the proper control tried to use the method, they'd be seriously injured if not outright dead"
[That's one hell of a Jutsu]
"Not Jutsu, but a method. Hehe, think about what that means"
["Method"...in other words, the changes you'll undergo after using it will be permanent as opposed to Jutsu effects which wear out once the user has exhausted their chakra...right?]
"Indeed"
[But you do know there are other, SAFER, techniques out there. I'm really enjoying myself here, what am I gonna do if you kick the bucket early? You're my only source of entertainment after all!]
"Gee, thanks. This scroll is definitely worth it. Because it's permanent, and not a temporary Jutsu, I won't have to worry about it being nullified by the enemy. And while I don't remember much about this story, you did tell me some of the big bads down the line will have such powers"
[Better safe than sorry huh? Are you SURE this is permanent?]
"The whole process is like increasing the atomic bonds of steel...like Diffusion Hardening...sort of. But on a WHOLE other level"
[So you'll be forever changed...this is a big decision. Getting a real sense of Deja vu considering we're in this lab again. Are you gonna follow through with this?]
It was not that long ago when Rei "remade" his body with Ōtsutsuki DNA and other various materials. Now in the same situation again, he couldn't help but chuckle at this turn of events
"Yes, but I'm prepared. Plus, I'll use a clone to test every area I'm supposed to refine before I use it on myself"
[Still very risky, very reckless, very...Naruto-like]
"This is his world after all. But I'm not totally reckless like him. Besides, what scientist doesn't take risks?"