Naruto : Reincarnated as Itachi Uchiha—Rise of the Uchiha Nation

A man who once despised Itachi Uchiha—viewing him as nothing more than a cold-blooded murderer—finds his fate cruelly twisted when he is reincarnated into the Naruto world… in the body of Itachi Uchiha himself. Reborn as a twelve-year-old Itachi, he awakens to a horrifying truth: the Uchiha Clan Massacre is only one year away. Armed with memories of his previous life and foreknowledge of the tragic future, he is bound to a mysterious and suspicious system known as the MUGA System — Make Uchiha Great Again System. Rather than granting instant godlike power, the system ties his growth to the strength, prosperity, and survival of the Uchiha Clan, forcing him to confront politics, manipulation, and destiny head-on. Skeptical of the system’s reliability and burdened by the weight of Itachi’s legacy, he must navigate the brutal ninja world—balancing power, intelligence, and emotion—while deciding whether the Uchiha are doomed to fall… or can rise once more. This story follows Itachi’s struggle to survive, defy fate, and determine whether it is possible to truly make the Uchiha great again—without becoming the monster history remembers. — Description from novelcodex.org