Several days ago
Rei was finishing up his Second Lifeline. He'd spent several hours listening to Notitita explain chakra's relationship and reactions with physics and the fundamental forces of this world...as per his request
[Namely, particle relations are the same as your original world. Chakra is frequently used to control matter and energy to certain degree, as you would put it, "Bending the rules". The most unique quality of this universe is the ability to convert chakra into energy and/or matter, and vice versa]
"I know bizarre phenomenon like bringing the dead back to life is just chakra-related science I've yet to understand, but how do I deal with it?" (Rei)
[You cannot as you are now. Subjects that include "raising the dead", "taking over bodies", "reality manipulation", and the so-called "soul" are currently subjects beyond your understanding. The author of this world created much he couldn't explain or comprehend, as that is what fiction is]
"I was afraid you'd say that" (Rei)
[In order to excel in this world, it is recommended you follow its rules, and not your own]
"..." (Rei)
[Are you satisfied with the results?]
"Yes, you've done more than enough Notitia. I am satisfied with the results. My Second Lifeline request has been completed" (Rei)
[...CONFIRMED...]
[...NOW ENDING SUPPORT MODE...]
Notitia was silent before Rei called out to again
"Back to normal?" (Rei)
[PHEW! Oh yeah! That's so much better! I hate being all prim & proper whenever you use a lifeline!]
"I should probably head back soon" (Rei)
[Whoa, whoa. Before you go, there's something I need to tell you before I...go to sleep]
{So even when I shortened the time, it still needs to rest...} (Rei)
The first time he used a lifeline, Notitia was greatly affected. Claiming he dragged it out for too long, it left Rei to himself for quite sometime before it emerged again
Have the role of his "guide", Rei didn't want Notitia out of commission. But even when he decided to move as fast as he could with this second attempt, it was still quite weary. The exact mechanics of this enigmatic, invisible entity only became more mysterious every time he conversed with it
[This recent incident has caused your body to undergo...another change]
"Is that so..." (Rei)
[You don't seem all that surprised, did you know already?]
"More like, I've had this feeling ever since I awoke in the hospital. A feeling of emptiness, no, of loss. His chakra is gone, I don't feel it anymore. What happened?" (Rei)
[It's the result of your rampage during the Yugito mission. You've had two chakra's within you competing for dominance, "Rei's" and your "Neo-Ōtsutsuki" chakra. You may not recall your time going all Obito on those poor Fuma but-]
{Oh, I remember} (Rei)
Rei still didn't inform Notitia he'd perfectly recalled everything, nor the details on his new power Kisshōten1Auspicious Heavens. The best assets were the ones he kept to himself until just the right moment
[You used Suiton, then Katon...but your reaction afterwards caught my attention. You screamed, "THIS FIRE...THIS WATER...IS DISGUSTING" and stopped using it altogether. It wasn't long before that unknown Yin-Yang related ability manifested]
"Ugh, the more I learn, the less I understand" (Rei)
Rei was still trying to rap his head around the events of that day. Having a power that could potentially go out of control at any given moment was gnawing at him since he awoke in the hospital. Since then, he's done nothing but study up on its nature
But due to the world's limited knowledge of In'yōton2Yin-Yang/Shadow & Light Style, there wasn't much he could do. Notitia was the best help he could receive, and even that wasn't enough
Contrary to what it claimed, Rei discovered Lifelines didn't grant it Omniscience, but a form of Omnipresence. It could see every aspect of the world at once, including any past event. Every event from this point and backwards were at its disposal
Notitia uses this information, along with knowledge of the manga's story, to make precision guess work based on somewhat reliable data in order to make highly accurate predictions of future events
"Why would my out of control Ōtsutsuki body call my Katon and Suiton disgusting? How does that relate to Yin-Yang style and Rei's chakra leaving my body?" (Rei)
[The chakra you've used for it so far wasn't yours, it was "Rei's". Just like a Tailed Beast and its host, these two chakras were fighting for dominance within you. And it looks like the Ōtsutsuki half won the battle]
"You're saying...his chakra was of lower quality or something? I mean, how does that even work? Why is Yin-Yang style related to this?" (Rei)
[There are so many misconceptions about this, about Yin-Yang, but I'll do my best to clear things up. First of all, how is chakra made?]
"By molding spiritual & physical energies, or yin and yang. Now that I think about it, all natures branch off from Yin-Yang, and every Jutsu is somewhat related to it. Does this mean every one can use Yin-Yang style?" (Rei)
[Not quite. As I've said, Ōtsutsuki control chakra on a level impossible for humans. Any Jutsu that involves bringing the chakra's composition to the highest possible level is classified as Yin-Yang Style. Only Ōtsutsuki-related techniques like the Gudōdama3Truth-Seeker Orbsor the Sage of Six Paths "Creation of all things" fall under this category]
Rei folded his arms and began to recall everything he knew about chakra
"In other words...In'yōton is simply the implementation of chakra in its purest form, which is why none categorize it as a Kekkei Genkai or Kekkei Tōta. Rather than simply being made of them, all other elements just branch off from it" (Rei)
[You're quick, that's a nice brain on your shoulders. Because only Ōtsutsuki can do this, they're obviously the most powerful. The only way to combat their insane powers is to have similar powers yourself]
{It's pretty much, Yin-Yang → Five basic nature transformations → Kekkei Genkai} (Rei)
Nearly all of the strongest characters within the story were revealed to have at least one connection to Ōtsutsuki by its climax. Rei now understood the reason his Ōtsutsuki cells purged "Rei's" chakra...it was due to their nature to possess the best chakra
Carrying the chakra of an average, human shinobi, how could his body accept it without complaint? His cells would no doubt find it "Disgusting" to have
[Controlling chakra comes natural to an Ōtsutsuki, thus they never have to "train" for things like affinities. They hate the concept of ninjutsu, calling it inferior. And truth be told, it is compared to them]
"Where does that leave me? How do I control my new power?" (Rei)
[Because you're not a normal Ōtsutsuki, but what we call a Neo-Ōtsutsuki, we're on uncharted territory now that you've awakened it]
"Uncharted territory, that's certainly not the vibe I was getting when you had me remake my body all those years ago" (Rei)
[We never accounted for you gaining Yin-Yang Style, or at least, not this soon. The only logical conclusion that comes to mind is to continue improving chakra control. Kneading chakra at the highest level brings one closer to Yin-Yang, learning how to do it may even trigger...new abilities]
"Like what? His bloodline isn't all that great" (Rei)
[That's only due to recessive genes, but now that you're only sporting Ōtsutsuki chakra, the same rules don't apply to you. Yin-Yang is the origin of all, the center. By reaching inside, you might discover something within "Rei's" heritage]
"Speaking of him, what about his chakra? Considering I was taking advantage of his average affinities, now that its gone, does that mean I have to start all over?" (Rei)
[You may find things slightly weaker, but that's only because you haven't gotten used to your new chakra yet]
"Crap" (Rei)
[Don't worry, now that only Ōtsutsuki chakra is flowing through your body, progression will naturally become many times faster. Considering the experience you already have, things should be normal in no time. This change is actually a blessing in disguise]
"Many times faster?" (Rei)
[Your new chakra is hax, you pretty much have an EXP booster]
"I have no idea what that means" (Rei)
[...You suck]
Notitia had a point, however. At the rate he was going, it was obvious his elemental ninjutsu would never become anything spectacular. This was proven by the fact the original character Rei died at an early age
"Okay, I can do that. Is there anything else I should know before you leave?" (Rei)
[One last thing, a warning. Don't mistake "Rei's" chakra disappearing as a sign you no longer have to find Ryūchi Cave. His soul may still be able to connect with you once more]
"Because I still have his DNA..." (Rei)
[Even though his soul isn't within you, as long as you're using his body, he has a tie to this plane. Chakra is the power to connect worlds after all, just like Edo Tensei4Impure World Reincarnation. If you don't deal with his soul, he'll just keep coming back, looking for an opportunity to take his body back]
{The concept is similar to matter...and like matter, his body and soul yearn to be one} (Rei)
Rei thought about the moment he first remade himself. That was the closest he had ever been to death since arriving in this world. It was soon after he demonstrated the ability to use Katon, despite the academy once telling him his only affinity was Yin and Yang separately
Since chakra can connect the living and dead, he surmised "Rei" took his opportunity to come back at that moment, but his chakra and presence were gone again
{Until I find Ryūchi cave, with the exception of the Black Scroll's Hidden Techniques, I'd best avoid "modifying" myself anymore} (Rei)
[Oh! Time's almost up! Any final questions before I go?]
"How long will you be gone this time?" (Rei)
[Considering this lifeline was only a few hours, just a few days or so. I'll be back soon, just don't go getting yourself in any dangerous situations while I'm gone]
"Kind of impossible in this world" (Rei)
[Fair enough, later]
After Notitia left, Rei made his way into Isshiki's proving grounds, just outside the lab for training
"I'll start with Katon and Suiton, since I have plenty of experience, it shouldn't take that long" {After that, I should probably focus on Kisshōten, which means practicing better chakra control} (Rei)
Present Time
Motoi and Rei were still buried under rubble. After failing to think of a way to escape while not accidently killing Motoi, whose leg was pinned under the rocks, Rei decided to leave the decision making...to someone else
{Focus on the center...focus...focus...} (Rei)
"Agh, how long has it been since we've been down here?" (Motoi)
"...!" {This chakra is?! Shit! Two hostiles are on their way here!} (Rei)
"..." (Motoi)
{And...there seems to one more...I don't recognize this one. Wow...it's a very fast one. Did they call for backup?} (Rei)
Rei was going to continue searching for more before realizing that sensing enemies now, is nothing but a distraction
{Whatever! Have to ignore that now, gotta focus! Come on, come on...almost there...} (Rei)
"?!" (Motoi)
ZUUUUU!
Chakra started to manifest around Rei's body
{What's he doing now?} (Motoi)
{...Kisshōten!} (Rei)
Several days ago
Rei was finishing up his Second Lifeline. He'd spent several hours listening to Notitita explain chakra's relationship and reactions with physics and the fundamental forces of this world...as per his request
[Namely, particle relations are the same as your original world. Chakra is frequently used to control matter and energy to certain degree, as you would put it, "Bending the rules". The most unique quality of this universe is the ability to convert chakra into energy and/or matter, and vice versa]
"I know bizarre phenomenon like bringing the dead back to life is just chakra-related science I've yet to understand, but how do I deal with it?" (Rei)
[You cannot as you are now. Subjects that include "raising the dead", "taking over bodies", "reality manipulation", and the so-called "soul" are currently subjects beyond your understanding. The author of this world created much he couldn't explain or comprehend, as that is what fiction is]
"I was afraid you'd say that" (Rei)
[In order to excel in this world, it is recommended you follow its rules, and not your own]
"..." (Rei)
[Are you satisfied with the results?]
"Yes, you've done more than enough Notitia. I am satisfied with the results. My Second Lifeline request has been completed" (Rei)
[...CONFIRMED...]
[...NOW ENDING SUPPORT MODE...]
Notitia was silent before Rei called out to again
"Back to normal?" (Rei)
[PHEW! Oh yeah! That's so much better! I hate being all prim & proper whenever you use a lifeline!]
"I should probably head back soon" (Rei)
[Whoa, whoa. Before you go, there's something I need to tell you before I...go to sleep]
{So even when I shortened the time, it still needs to rest...} (Rei)
The first time he used a lifeline, Notitia was greatly affected. Claiming he dragged it out for too long, it left Rei to himself for quite sometime before it emerged again
Have the role of his "guide", Rei didn't want Notitia out of commission. But even when he decided to move as fast as he could with this second attempt, it was still quite weary. The exact mechanics of this enigmatic, invisible entity only became more mysterious every time he conversed with it
[This recent incident has caused your body to undergo...another change]
"Is that so..." (Rei)
[You don't seem all that surprised, did you know already?]
"More like, I've had this feeling ever since I awoke in the hospital. A feeling of emptiness, no, of loss. His chakra is gone, I don't feel it anymore. What happened?" (Rei)
[It's the result of your rampage during the Yugito mission. You've had two chakra's within you competing for dominance, "Rei's" and your "Neo-Ōtsutsuki" chakra. You may not recall your time going all Obito on those poor Fuma but-]
{Oh, I remember} (Rei)
Rei still didn't inform Notitia he'd perfectly recalled everything, nor the details on his new power Kisshōten1Auspicious Heavens. The best assets were the ones he kept to himself until just the right moment
[You used Suiton, then Katon...but your reaction afterwards caught my attention. You screamed, "THIS FIRE...THIS WATER...IS DISGUSTING" and stopped using it altogether. It wasn't long before that unknown Yin-Yang related ability manifested]
"Ugh, the more I learn, the less I understand" (Rei)
Rei was still trying to rap his head around the events of that day. Having a power that could potentially go out of control at any given moment was gnawing at him since he awoke in the hospital. Since then, he's done nothing but study up on its nature
But due to the world's limited knowledge of In'yōton2Yin-Yang/Shadow & Light Style, there wasn't much he could do. Notitia was the best help he could receive, and even that wasn't enough
Contrary to what it claimed, Rei discovered Lifelines didn't grant it Omniscience, but a form of Omnipresence. It could see every aspect of the world at once, including any past event. Every event from this point and backwards were at its disposal
Notitia uses this information, along with knowledge of the manga's story, to make precision guess work based on somewhat reliable data in order to make highly accurate predictions of future events
"Why would my out of control Ōtsutsuki body call my Katon and Suiton disgusting? How does that relate to Yin-Yang style and Rei's chakra leaving my body?" (Rei)
[The chakra you've used for it so far wasn't yours, it was "Rei's". Just like a Tailed Beast and its host, these two chakras were fighting for dominance within you. And it looks like the Ōtsutsuki half won the battle]
"You're saying...his chakra was of lower quality or something? I mean, how does that even work? Why is Yin-Yang style related to this?" (Rei)
[There are so many misconceptions about this, about Yin-Yang, but I'll do my best to clear things up. First of all, how is chakra made?]
"By molding spiritual & physical energies, or yin and yang. Now that I think about it, all natures branch off from Yin-Yang, and every Jutsu is somewhat related to it. Does this mean every one can use Yin-Yang style?" (Rei)
[Not quite. As I've said, Ōtsutsuki control chakra on a level impossible for humans. Any Jutsu that involves bringing the chakra's composition to the highest possible level is classified as Yin-Yang Style. Only Ōtsutsuki-related techniques like the Gudōdama3Truth-Seeker Orbsor the Sage of Six Paths "Creation of all things" fall under this category]
Rei folded his arms and began to recall everything he knew about chakra
"In other words...In'yōton is simply the implementation of chakra in its purest form, which is why none categorize it as a Kekkei Genkai or Kekkei Tōta. Rather than simply being made of them, all other elements just branch off from it" (Rei)
[You're quick, that's a nice brain on your shoulders. Because only Ōtsutsuki can do this, they're obviously the most powerful. The only way to combat their insane powers is to have similar powers yourself]
{It's pretty much, Yin-Yang → Five basic nature transformations → Kekkei Genkai} (Rei)
Nearly all of the strongest characters within the story were revealed to have at least one connection to Ōtsutsuki by its climax. Rei now understood the reason his Ōtsutsuki cells purged "Rei's" chakra...it was due to their nature to possess the best chakra
Carrying the chakra of an average, human shinobi, how could his body accept it without complaint? His cells would no doubt find it "Disgusting" to have
[Controlling chakra comes natural to an Ōtsutsuki, thus they never have to "train" for things like affinities. They hate the concept of ninjutsu, calling it inferior. And truth be told, it is compared to them]
"Where does that leave me? How do I control my new power?" (Rei)
[Because you're not a normal Ōtsutsuki, but what we call a Neo-Ōtsutsuki, we're on uncharted territory now that you've awakened it]
"Uncharted territory, that's certainly not the vibe I was getting when you had me remake my body all those years ago" (Rei)
[We never accounted for you gaining Yin-Yang Style, or at least, not this soon. The only logical conclusion that comes to mind is to continue improving chakra control. Kneading chakra at the highest level brings one closer to Yin-Yang, learning how to do it may even trigger...new abilities]
"Like what? His bloodline isn't all that great" (Rei)
[That's only due to recessive genes, but now that you're only sporting Ōtsutsuki chakra, the same rules don't apply to you. Yin-Yang is the origin of all, the center. By reaching inside, you might discover something within "Rei's" heritage]
"Speaking of him, what about his chakra? Considering I was taking advantage of his average affinities, now that its gone, does that mean I have to start all over?" (Rei)
[You may find things slightly weaker, but that's only because you haven't gotten used to your new chakra yet]
"Crap" (Rei)
[Don't worry, now that only Ōtsutsuki chakra is flowing through your body, progression will naturally become many times faster. Considering the experience you already have, things should be normal in no time. This change is actually a blessing in disguise]
"Many times faster?" (Rei)
[Your new chakra is hax, you pretty much have an EXP booster]
"I have no idea what that means" (Rei)
[...You suck]
Notitia had a point, however. At the rate he was going, it was obvious his elemental ninjutsu would never become anything spectacular. This was proven by the fact the original character Rei died at an early age
"Okay, I can do that. Is there anything else I should know before you leave?" (Rei)
[One last thing, a warning. Don't mistake "Rei's" chakra disappearing as a sign you no longer have to find Ryūchi Cave. His soul may still be able to connect with you once more]
"Because I still have his DNA..." (Rei)
[Even though his soul isn't within you, as long as you're using his body, he has a tie to this plane. Chakra is the power to connect worlds after all, just like Edo Tensei4Impure World Reincarnation. If you don't deal with his soul, he'll just keep coming back, looking for an opportunity to take his body back]
{The concept is similar to matter...and like matter, his body and soul yearn to be one} (Rei)
Rei thought about the moment he first remade himself. That was the closest he had ever been to death since arriving in this world. It was soon after he demonstrated the ability to use Katon, despite the academy once telling him his only affinity was Yin and Yang separately
Since chakra can connect the living and dead, he surmised "Rei" took his opportunity to come back at that moment, but his chakra and presence were gone again
{Until I find Ryūchi cave, with the exception of the Black Scroll's Hidden Techniques, I'd best avoid "modifying" myself anymore} (Rei)
[Oh! Time's almost up! Any final questions before I go?]
"How long will you be gone this time?" (Rei)
[Considering this lifeline was only a few hours, just a few days or so. I'll be back soon, just don't go getting yourself in any dangerous situations while I'm gone]
"Kind of impossible in this world" (Rei)
[Fair enough, later]
After Notitia left, Rei made his way into Isshiki's proving grounds, just outside the lab for training
"I'll start with Katon and Suiton, since I have plenty of experience, it shouldn't take that long" {After that, I should probably focus on Kisshōten, which means practicing better chakra control} (Rei)
Present Time
Motoi and Rei were still buried under rubble. After failing to think of a way to escape while not accidently killing Motoi, whose leg was pinned under the rocks, Rei decided to leave the decision making...to someone else
{Focus on the center...focus...focus...} (Rei)
"Agh, how long has it been since we've been down here?" (Motoi)
"...!" {This chakra is?! Shit! Two hostiles are on their way here!} (Rei)
"..." (Motoi)
{And...there seems to one more...I don't recognize this one. Wow...it's a very fast one. Did they call for backup?} (Rei)
Rei was going to continue searching for more before realizing that sensing enemies now, is nothing but a distraction
{Whatever! Have to ignore that now, gotta focus! Come on, come on...almost there...} (Rei)
"?!" (Motoi)
ZUUUUU!
Chakra started to manifest around Rei's body
{What's he doing now?} (Motoi)
{...Kisshōten!} (Rei)
