From Corpse to Crown: Reborn as a Mortician in Another World - Chapter 24: Stonewalled

Finding himself in an Last Airbender without an airbender around, a transmigrator waterbender goes on an adventure to stop the worst from happening to him.

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.

I became the Heavenly Demon’s dog.

Weiss is an ordinary young man caught in the changing times who is studying magic from an unknown natural event. When he feels weak and helpless in facing a world that is constantly changing and filled with magic, he awakens his secret ability, the “Maid Order”. Special abilities that make him a “Master” who will be respected by the “Maids” who are loyal to him.