The Great Mage Returns After 4000 Years (Web Novel KR) - Vol 2 Chapter 481

The meteor pierced the sky and also pierced the peace of the world.

Transcendent power comes to the world, who is watching in the dark, and who is whispering in my ear.

When the roar shatters the sky, when the power steps down the abyss, when all life and death are dominated… They call me – God.

- Description from novelbuddy

A man who was once called the world strongest agent ended up becoming a teacher after his retirement to train the new generation of agents. After many years of training his disciples, he is killed at the age of 60 by the ploy of a secret organization and was reincarnated in another world with all his past memories.Though he was surprised by the magic and the strange species of that world, he adapted very fast 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 tight 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 new students.

Shi Qing Xia is practically an angel.

Kind, sweet-hearted, and good at her studies, she was admitted to the top university in Taipei.

However, the living expenses for the metropolitan city were far greater than she had ever imagined, so she started to work as a private tutor for wealthy families to make ends meet.

On her first day of work, she met Zhao Yi Bo and Zhao Yi Xuan, a pair of neglected 16-year-old genius twins whose prosperous and wealthy parents heartlessly abandoned in Taiwan. Shi Qing Xia found them to be gentle, compassionate, friendly, clever, mysterious, pitiful and attractive.

But appearances can be very deceiving…

Because behind those sweet smiles…

Deeply twisted and cruel demons lurked, waiting to rip apart the wings of this angel, condemning her to an eternity of conflicted bittersweet suffering — a rollercoaster ride of a heart-wrenching, twisted, and tragic romance more extreme than what someone so innocent could possibly imagine.

- Description from Novelupdates

Hiding in the Cold Palace and eventually becoming a Boss of Sorts. Li Mu was transported to a fantastical world and became a measly eunuch of the State of Xia. Despite having initially thought that his life would be a miserable one, he had unexpectedly acquired a check-in system.