Kill the Sun - Chapter 931 Fusion

The Fourth Shinobi World War is over. All enemies are defeated. Finally, a long peace reigned in all countries. The Seventh Hokage laid down his arms and lost all his Youth Power. One dream, the goal for which he spent his whole life, has been achieved. His path is over. Is this really the end? Could it end so easily? What if the Savior of this World turns into an arrogant and cunning ruler?Perhaps no one would ever have been able to predict such a result. On that day, everything changed ... Countries, riches and power, the most beautiful women and their young daughters - he will subdue them all! The Seventh Hokage with the strength capable of conquering the heavens chose a different path, now he will take everything for himself and pave the way to absolute world domination!

An ordinary sect cultivator, with the help of the immortal mansion, gradually grew up in the cruel world of immortality, and his mind and body transformed together.

Mortal flow, partial dark wind.

- Description from novelbuddy

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.