Citadel for All: The Only Unit Angel at the Start of the Game - Chapter 440

A world-famous hacker and daughter of the most powerful criminal family who ruled the international underworld for many generations is killed when their organization is annihilated in a single night.

Zhao Rong boasts super medical and martial skills, yet he keeps a low profile as an ordinary college student. When he gets his first part-time job, which requires him to pursue a school beauty whose boyfriend is a killer, Zhao knows his peaceful life ends.

One night she gets drunk and mistakes the most well-known Mafia boss for a host and intends to sleep with him.

Oh my! What should I do? It’s best to run away!

- Description from Novelupdates

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.