(December, year 54 AK)
Coming to a conclusion, about that without letting his own body to grow over a few more years naturally there is nothing much he could do to quickly increase his own power, after thinking it through Yuta wasn't very disappointed with that conclusion.
He wasn't disappointed because the time inside a time-loop and the time that he lives through, following the current of the River of Time, is not much different in the end from his perspective. As long as there is no unsurmountable enemy appearing on his path that he has to defeat to continue moving forward, he could just live a normal ninja's life for a few more years and just see what happens.
After all, as Yuta calculated, when his physical body will reach its peak condition by the age of twenty-twenty-five, his body would be able to handle much more spiritual energy. And with that, Yuta believed that he will have at the very least about two to three hundred years of subjective time to figure out how to deal with the problem of constantly growing spiritual energy and the energies imbalance as a result of that.
As to how exactly he would do that, Yuta wasn't too worried about it right now. There are some ideas about the possibilities of improving his physical body and physical energy as a result, but all of that will come at a later stage, when Yuta will have much more influence, knowledge and skills. And procrastination and postponing the problem for the future him because of the perceived high difficulty and innate laziness has nothing to do with it, nothing at all...
This problem is not something Yuta could deal with right now either way. When he was just a Genin and has almost no autonomy of what he does and even the direction of his training right now is closely guided by Shisui.
Yuta understood that if he asks Shisui right now to provide him with training materials and guidance for, for example, medical ninjutsu, Shisui wouldn't understand why it would be appropriate for Yuta to switch his training focus right now from the area he was excelling in – genjutsu, to something completely new for him and what will require multiple years of study to even begin using medical ninjutsu on a beginner level.
Yuta understood that there is no way in hell he would be able to explain why his desire to learn a completely different set of skills would be a good idea for him right now, at his current early stage, when not even a full year passed since his early graduation. He can't just say to Shisui that he will train in a time-loop and that the training of a completely new skill won't harm his genjutsu development.
Although Yuta also believed that Shisui already had some suspicions about his training progress.
Whenever Shisui was teaching him something new, like genjutsu or the recent Body Flicker jutsu, Yuta has to use a time-loop to quickly learn and master it, so it won't look too suspicious for him, a supposedly talented genius, to fumble some jutsu over and over and to master it slowly.
Yuta was always trying his best to smoothen up all those inconsistencies in his training progress by training in a time-loop, but still, Yuta was aware that not everything was successfully smoothened by that. Yuta was also using a chakra suppression technique at all times to smoothen up his rapid surges in chakra growth when he exits long time-loops, although he was aware that such simple technique won't be able to fool Shisui's Sharingan.
So, by now Yuta pretty much knew that Shisui must be suspecting something, but Yuta wasn't really worried about that, since Yuta believed that even in Shisui's wildest assumptions he wouldn't be able to imagine that Yuta was able to time-travel.
Yuta briefly considered the idea of using those inconsistencies in his training progress and gains to use it as an excuse for asking for a training materials for medical ninjutsu or fuinjutsu, telling Shisui some fabricated lie as an excuse for him to start learning new areas and ninja arts, but then he dismissed the idea.
The lie would be too crude and full of holes, while Yuta absolutely cannot tell the truth even to Shisui. If anyone ever learns the truth - that's when Yuta stops being completely safe and invincible with his time-travel, and becomes someone who could be cornered and dealt with, same as everyone else.
Yuta understood well, that he was only able to remain invincible in this world until no one knows his biggest secret. As long as no one knows, he could escape into the past at any moment. But with how dangerous, shrewd and canning the experienced ninjas are, especially those that had reached Kage level, they could find a way to corner and dealt with even him, one way or another, so Yuta absolutely cannot allow this intel to be leaked into the world, even if it is Shisui, his closest friend.
'So, no fuinjutsu or iryojutsu(medical ninjutsu) for me for the time being, I guess... Maybe after a year or two, when I'll get a promotion to Chunin rank, I'll be able to get what I want...'
'And what exactly do I want? Stupid question. I want everything, naturally... Why should I limit myself to one or two areas of expertise or ninja arts when I'm the only one in the world who is not limited by time? Exactly.'
'Genjutsu are great, and I love it, and I absolutely will try my best to develop my genjutsu to the level when it could be effectively used even against Kage level monsters, but that doesn't mean I should limit myself just to genjutsu. Other areas and ninja arts are great as well, and I would like to learn and master all other ninja arts eventually, it is only natural.' Yuta thought with as he completed his physical training routine and switched straight to genjutsu training, further honing and polishing his two original genjutsu.
Although he won't be able to improve it much further like that, he still has time and unspent chakra, so he naturally continued his training session regardless.
'Am I slowly becoming a second Orochimaru?' Yuta thought suddenly, 'Even if I am, so what? Either way I will be much better than Orochimaru, since I'm not pressed by the limited time to learn all jutsus in the world like him, nor I'm as obsessed with that goal as he is. I'm not going to resort to some half-baked jutsu that has so many side effects and complications like his immortality jutsu in early stages, basically during the whole Naruto story, with all that body rejection thing each three years and stuff like that.'
'I'm also not very willing to become a mad scientist like Orochimaru, that performs invasive human experiments left and right, leaving hundreds of corpses behind everywhere he walks, that is not my style, never will be.'
'After all, why rash and do all of that messy stuff when the time itself is on my side?'
...
'That Stone ninjas, only the Jonin among them was seriously dangerous to us.' Yuta's thoughts gravitated back to the fight, and he continued to analyze it, 'Those three other ninjas, they were Chunins most likely. And without me being overconfident and underestimating them, I wouldn't be killed by that girl Maki back then, I could only blame myself for that. After completing a bunch of missions and having to fight some relatively weak ninjas a couple times in the past months I had become a bit overconfident with my skills, and so I did deserve that stone spike piercing my chest back then, will be smarter next time...'
'Those two other Chunins, already forgot their names, that Hikari was fighting, they weren't anything special either. Although all three of those Stone Chunins were skilled and even capable of killing me one on one if I were to become careless, they aren't much compared to that Jonin Keisuke.'
'Also, back when I was helping Hikari to deal with those two Chunins, I had some difficulty to do so since both of them were skilled and quite fast. I couldn't just paralyze one of them outright and kill him, since the other one would intervene and protect his teammate and dispel the genjutsu, so I had to come up with some trick to separate them first.'
'It is very inconvenient that my Shadow Chains genjutsu is a single target jutsu, sigh, but nothing could be done about that right now, I simply can't handle right now the amount of chakra it would require to cast the jutsu on two targets at once. I might be able to cast it on multiple targets with Genin level chakra, but when it comes to Chunin level opponents with chakra levels close to my own – it still won't be possible for me to affect multiple targets like that for the time being.'
'Now that I think about it, it would've being easier to use Shadow Cloak on them instead, but they already spotted me killing Maki and start coming in their direction, so it wouldn't be guaranteed that they would fall for my Shadow Cloak right away either, and I also wanted to keep it hidden for Keisuke back then, although it didn't work against Keisuke either way, up until the very end.'
'Keisuke, huh... He was fast, very fast, for me as I am now, coming anywhere close to him is suicide, I still remember that casual kick that messed everything inside my chest, not a big fan of that...'
'And his chakra reserves, although his chakra was mostly depleted by the end of the fight, from the beginning to the end of it he didn't show any weakness or signs of getting tired. From the beginning to end he was defending and attacking at the same time, throwing one ninjutsu after another like there was no end to his chakra at all, and he almost won the fight too...'
'His Earth Style ninjutsu... Well, not like I know much about elemental ninjutsu in general, most of my knowledge is from my previous life, and since Keisuke didn't scream jutsu's names, I don't really know much about what jutsus he was using. Although his ninjutsus seems to be very proficient at defense, easily and quickly blocking everything we had thrown at him, and he seems to be spending much less chakra on his defensive ninjutsus than Itachi was spending on his offensive Fire Style attacks...'
'His offensive Earth Style was also quite formidable and wide-ranged, he was pushing us around with it and the only choice we had is to dodge it from the distance, and as a result we were losing more and more initiative during the fight, and fight was turning more and more into defensive one instead. Not a great position to be forced into when you have to deal with your enemy before he deals with you...'
'Itachi was fighting almost on par with Keisuke, but he was being outmaneuvered with Keisuke's superior combat experience and tactics, that's why the whole battle turned the way it did, not because the three of us were lacking in strength compared to Keisuke. But this weakness of Itachi is no big deal after all. I assume that after this fight Itachi has already become much more experienced, learning a great deal from it. After all, it is Itachi, I would be surprised if he won't become much stronger after that struggle.'
...
'Hm, Itachi becoming much stronger, and Hikari, with her new ability, even although she won't reveal it casually, is also becoming much stronger...'
'While my answer to that – is that I have to wait a year or two before going for another level-up... Sigh, I guess nothing really could be done about that... Still, one day I will surpass both of them, after all, time is on my side...'
--- AN ---
I know, a bit too much thoughts and analysis and too little action in this chapter, but at least the chapter is significantly bigger than usual. Also, I felt like I have to make a chapter like this one to clarify some misunderstandings that you guys ask me often about, like why Yuta doesn't do everything he possibly could to solve the energies imbalance problem right now, for example, or why he didn't learn medical ninjutsu right now. Also, I think this is the last chapter of "eight-year-old" Yuta, time skip is coming.
*Em... now that the me from the 'future' are reading this note, I should say that there is not much of a time skip in the next chapters like I was implying here... Yea, sorry about that...
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