The Uchiha-Senju Immortal

A young man named 'Ale' was known as the greatest doctor that ever existed, after surpassing all of the current knowledge about genes and the human body, he started to develop something to make the 'Perfect Body', on an experiment, however, an explosion happened and he died instantly. Instead of going to Heaven or to Hell, the young man was on the void, just with the space and darkness around him for millions of years. While pondering over his existence and questions that always bothered him, the more than one million years old boy suddenly reincarnated as 'Senju Shiro' at the Era of Warring States. Note: It's an alternative universe, changes are INEVITABLE, if you want something that follow completely the cannon, this isn't for you. Disclaimer: I do not own Naruto franchise or the cover, picked it on google.