I've Become a Genius Actor - Chapter 30:

A master of Chakra Cultivation sacrifices everything - only to be reborn with a second chance.After giving his life to save his world, Alaric awakens in the body of a child. In this new realm where power is measured in tiers, bloodlines, and the strength of one's oaths, Chakra Cultivation is an unknown path.As Alaric purifies his chakras, each one unlocking profound abilities across body, mind, and soul, he gains an edge no native warrior can match. But his true test awaits in the Tower of Trials—a rite of passage for the world's young elites, offering immense rewards to those who can climb its treacherous heights. No one has ever reached its highest levels.If mastering his reborn powers wasn't hard enough, his journey will forge a bond with an entity of unimaginable strength - and lead him to lands where no mortal has dared to tread.

A man who was once called the world’s strongest agent ended up becoming a teacher after his retirement, to train a new generation of agents. After many years of training his disciples, he was killed at the age of 60 by a secret organization’s ruse and was reincarnated in another world with his memories intact. Though he was surprised by the existence of magic and the strange species in that world, he quickly adapted to his condition as a newborn and took advantage of it. He acquired special magic and gained a massive amount of strength thanks to his rigorous discipline, in order to reach his goal: Resume his career as a teacher which he left halfway through in his previous life. This is the story of a man, who, based on the memories and the experiences of his previous life, became a teacher who travels through the world with his students.

In a world where strength reigns supreme and only the strong are revered, conflict and injuries are commonplace.

What if something made Naruto the dead-last that everyone perceives him to be? What if he really wasn't as weak as he appeared? The true Naruto, unleashed upon the shinobi world! AU story starts at the Konoha Invasion arc and continues from there..