The Uchiha - Senju Immortal

''Just to let you remember: Ninjutsu isn't allowed...'' My father said with a laugh before he said ''Start!''

While my Taijutsu is indeed weak, I still knew some martial arts from my previous but I decided not to use it, for now, running straight towards my father, I sent a simple punch just to see myself flying back to my previous position, lying in the ground, my father absolutely only held back his power enough for me to stay alive.

Suddenly, a refreshing feeling passed through my body as I the broken bones regenerated instantly and I felt stronger than before by at least 10%, do I have Zenkai? I guess this is one of the benefits of having a body literally made of Natural Energy, I'm immortal, this is amazing, I won't need to find a way to become one, haha!

''Did you see that, father? I regenerated instantly!'' I said, feeling a rare excitation that unfortunately died as soon as I saw a devilish smile on my father's face ''Yes... that's amazing!''

Aw, sh*t... here we go again, picking a kunai, I threw it to my father, that dodged and simply looked at me, smiling, I created a small space opening to make the kunai go into it and then another one behind my father, the kunai went back straight to my hand and my father, unprepared to the sudden appearance of the kunai on my hand, had his hand barely cut.

With an astonished expression, he asked me ''Little brat, how did you do that?''

Sooner or later, my space manipulation will be discovered but I plan to hide it for some time ''I'm not sure of it myself, it's like I can control the direction of it''

Well, it's not totally a lie and my father accepted but said ''I understand, however, you can't use this on Taijutsu training, I can feel that your speed increased some times, does it increase after you are seriously injured and then you regenerate?''

I swear that I felt fear this time because my father said this with a smile but I still nodded and regretted it instantly as he said ''Son, I love you but this will make you strong enough to the war that's coming''

He led me towards a mountain and then, I prepared to fight against him to train myself but in the start, my father just taught me Taijutsu normally, pointing my flaws, I absorbed all of the knowledge like a sponge, this kept going for a month, when my father said ''I already taught you everything that I know about Taijutsu, now, we will start your physical training, let's start with the basic things, run around this mountain without using chakra to reinforce yourself for at least 10 times, you have to make your body catch up with your reserves of chakra!''

''Damn!'' I cursed loudly though I know it's wartime for at least some decades and getting stronger is essential, it's still terrifying to run around this mountain, well, what can I do, right? I started to run around this monstrous demon.

I knew that running even one time around it would be very hard... after around ten minutes, I completed a l.a.p, something that wouldn't really be possible in my previous life, this mountain is simply... huge!

And here am I, breathing heavily after completing the first l.a.p, my entire body is sweating and my body hurts, however, even in my previous life, I always trained to my limits and I know I'm not even near it so I started to run again, and again...

After the tenth l.a.p, I felt that if I did one more step, my bones would break, I have to admit, my father is smart, just from examining my body, he knew that ten l.a.p.s were above my exact limit, basically, he said for me to run ten times around it to test my determination and 'will', to go past my limits!

*Pá!*

I fell on the ground and couldn't move my body, when my regeneration was used last month after my father almost killed me, I grasped that feeling and in the past month, I learned how to control my own regeneration, controlling this thing is harder than controlling space but the fact that I'm made of Natural Chakra made it easier, so, in these ten l.a.p.s, I didn't use it to regenerate my lost stamina or my body state to the peak.

Using it after I broke my body limits was the best use of my regeneration and I did so, a refreshing feeling passed through my entire body as all of my fatigue disappeared and my body returned to its peak, no, I surpassed it by many times!

However, I still have a long way to catch up with my chakra reserves, after the first time I refined chakra, the refining slowed down and I'm currently on a bottleneck, the reason is that my body has to catch up, you see, because of me being made of Natural Chakra, it has some requirements, my physical body has to catch up with my reservers, otherwise, kaboom, haha...

In the past month, my Sharingan hadn't evolved, I predict it to evolve in two years, no, it will evolve in probably one and half years if I don't experience a huge emotion, if I have to judge my own physical body strength without considering all of my Taijutsu techniques and experience, it's only at genin or C-Rank Shinobi, that's the current way of strength measurement.

C is the same as Genin, C+ is the same as Elite Genin, which is basically the peak of strength a Genin can have, B is the same as Chunin, B+ is the same as Elite Chunin, the peak strength that a Chunin can have, A is the same as Jounin, A+ is the same as the peak a Jounin can have, there isn't an exact measurement of an Elite Jounin, that is a Jounin specialized in specific areas, but in my opinion, it can be considered B++.

Next is the peak of the current Shinobis: Clan Leader strength, it's the same as having the strength of a normal Kage, it can also be considered S-Rank, above this is S+ and the only people that have this strength currently is the Senju Clan Leader, Uchiha Clan Leader, and Kaguya Clan Leader.

There's above the S+ but from what I know through my father, there is no one with this strength, basically, Uchiha Madara and Senju Hashirama were the first to surpass this level of strength on the Warring States shown in the anime or manga.

The first day of training my physical strength ended with me sleeping after running 10 l.a.p.s, training the physical body is much difficult than training Chakra and I guess it will take at least another month to catch up, if not because I'm made of Natural Chakra and my talent is basically the highest, it would take at least a year for a normal genius person in growth stage like me and at least two years for an ordinary person in growth stage, I'm literally an abomination, not in the bad way, though, by the way, now I can open a small space opening enough to fit a small kid like me.

I'm really sleepy now because of the training, I guess I'll sleep, goodbye again, everyone!