Naruto: I Survived the Chaos to Become the God of Shinobi

The pace is relatively slow. If you dislike protagonists who grow slowly and endure humiliation, you can skip to the Uzumaki Village arc, by which time the protagonist will have already become incredibly powerful.

At the dawn of the First Great Ninja War, Uchiha Cang was drawn into the undercurrents and internal strife of Konohagakure. As a pawn placed on the chessboard, he repeatedly found himself in perilous situations, a mere Chunin constantly facing assassination attempts. In despair, the 'Heaven Rewards Diligence' destiny awakened!

From then on, when he cultivated any Ninjutsu or Taijutsu, there were no longer any elemental energy limitations, no aptitude thresholds, and no bottleneck restrictions. Ultimately, the God of Shinobi was born, integrating ultimate techniques such as Hashirama's True Several Thousand Hands, Madara's Complete Body Susanoo, and Guy-sama's Night Guy!

(A lighthearted power-up story)