MTL - Supreme Throne of Doom - Chapter 65 Su Yang crisis

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.

A tale about the former leader of a special organization served under royalty, now leaving his past life behind and unintentionally getting involved with the martial world.

- Description from Novelupdates

I once believed I was the heroine of a modern fairytale, blessed with beauty, wealth, intelligence, and a powerful legacy. Men adored me, women envied me, and I was engaged to the most desirable man, Cole Fay. My life seemed perfect, a dream where I held the starring role. But on my eighteenth birthday, that illusion crumbled. The truth hit me hard: I wasn’t the protagonist, nor even the villain or a side character. I was just cannon fodder, a disposable part of someone else’s story. But when fate recognized the cruel joke of my life, I was granted a second chance. This time, I’ll write my own story, living for myself. And this time . . . I will never love you again.

Benedict was transported to a world of cultivation and awakened the Invincible Domain system. Within this domain, he was invincible!