No More Pain For This Villain. - Chapter 6 First Encounter,

First-Generation God King Tang San, with a trace of divine consciousness, roamed the universe, searching for the world where his wife had reincarnated. Guided by that divine consciousness, he arrived at a place called Demon Monster Land, only to find that it was a world where humans were as lowly as livestock…

In the eighth year of the apocalypse, Qin Wu was betrayed and thrown into a pile of zombies.While dying, she regretted not taking a chance and pursuing her beloved man.After being reborn, Qin Wu only wanted to take revenge and pamper her beloved Mo Chenxuan.While he survived the apocalypse, Mo Chenxuan realised he was wrong. The person he truly loved was not his girlfriend before the apocalypse but the secretary who accompanied him through thick and thin.After he was reborn, Mo Chenxuan only wanted to dominate the apocalypse and make Qin Wu the happiest woman in the world.

Ling Fei, the son of a fisherman in Sanxian Island, was accidentally involved in a mysterious continent–Arad, after learning that his celestial destiny was shallow and that he had no way to ascend.

Sword, there are unique adventurers here. Ling Fei, who has just arrived, has a mysterious mission and an ancient blood. The silent Grand Forest is roaring, the ancient ruins of the king are lamenting, and it is unknown what the legendary headless horseman is chasing.

On the ground, Ling Fei gets acquainted with his partners, takes risks, and becomes a legend!

- 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.