The Heir is Here: Quiet Down, School Prince! - Chapter 110 - Leave Me Alone

Demons in Academy of Light are described as vile, dark, cruel, evil, impure, and a whole lot of other things. At least, that’s how they’re portrayed in the game—a sacred land where demons and dark energies aren’t supposed to exist. That’s how it was supposed to be... So what the hell am I supposed to do now? Thanks to my rotten luck, my soul ended up possessing the lowest-ranking demon, the one who dies at the very beginning of the story... I’m screwed! I have no other options left... If I want to survive, I have to kill the protagonist.

To save the hopeless Dark Fantasy World, I held back my tears and destroyed the world, then killed the Demon King and returned.

Now, I’m trying to save the world using the ‘System’ I gained as the ‘Regressor’s Privilege’… but the Main Heroines have also awakened their memories of the previous timeline.

God damnit.

Han Yang never thought he would one day sell himself into a marriage with another man. He believed his life would be mundane but that man, named HeLian Qing, broke his pre-planned life. Parental debt, a child’s compensation, he had no chance whatsoever to resist, he has no ability to resist.

A master assassin transmigrates into an interstellar era.

Other players were responsible for competing in the e-sports arena, while he was responsible for stringing up and beating up the other players.

His sword was hidden during the peak of day, and he was a gentleman who arrived in a flash of light;
As a vanguard of the eternal night, he was the variable between life and death in the world.

“As you know, the Star League’s difficulty levels are arranged in this way:
Paradise < Simple < Normal < Difficult < Nightmare < Hell < [Tyron Odin]”

- Description from Novelupdates