World Teacher - Isekaishiki Kyouiku Agent

A man once known as the world's strongest agent chose to become a teacher after retiring, aiming to train the next generation of agents. After years of mentoring his disciples, he was tragically killed at the age of 60 by a secret organization's scheme. He was then reincarnated in another world, retaining all his past memories. Though initially surprised by the magic and unfamiliar species of this new world, he quickly adapted to his new life as an infant and leveraged his unique situation. Through rigorous discipline, he acquired powerful magic and immense strength. His ultimate goal was to resume his teaching career, which he had left unfinished in his previous life. This is the story of a man who, drawing on his memories and experiences from his past life, became a wandering teacher, traveling the world with his students.