for me, the best naruto fanfic. Some people complain a lot in the comments that the MC is very weak, that he hasn't done anything in the 10 years that he has been living in the world of naruto. And that after getting the Tenseigan, he's still pathetic, beta MC etc... Don't pay attention to those comments, I bet they haven't even read beyond chapter 20. They criticize the novel badly without reading or understanding it first.
To begin with, our MC is reincarnate in the world of naruto with nothing.
He has no wishes or anything like that, they dump him in the Hyuga clan where they mark him with the seal.
He tells us about a more realistic Naruto world, where he makes it clear that talent is about what lineage you have. Being the MC with zero talent and no realistic chance of improving beyond Jounin the MC decides to take a chance and go another route, which, if it works for him, he will be able to improve beyond what he would have achieved through normal means.
He becomes a disciple of Orochimaru to study genetics and achieve the tenseigan. Some people will say that he was Orochimaru's disciple and was still weak. But the reason is that Orochimaru didn't see any talent in him so he didn't train him, on the contrary, he was a good researcher so he made him his right hand man for scientific investigations.
Many criticize that when he gets the Tenseigan, he is too weak and that the Tenseigan he has is also too weak.
No, the tenseigan that the MC gets isn't weak, the MC is weak, like Nagato with the Rinnegan. The Tenseigan being the MC's own and not transplanted, the Tenseigan takes care of his MC. Without enough chakra to be a Tenseigan wielder, the Tenseigan is weakened to not killing the user.
And thanks to the fact that the tenseigan awakens, the MC purifies his bloodline by improving the talent that he had, with the passage of time he can become stronger.
With the birth of Naruto and the beginning of the Canon, the MC is forced to take drastic measures to increase his power enough to take on madara and kaguya.
And from there is where the story improves a lot, the character development is excellent, so much so, that if you read everything in a row you will not realize that the MC has changed, but if you read how the MC behaved in the first chapters, and then you read in the last chapters, you will realize that he is more mature and more calculating. Not only our MC but also Shisui, the MC's best friend