MTL - Plundering the Heavens - Chapter 23 Demon

As a promise, he went out into the world as an assassin. 3 years later, after becoming the Supreme Assassin, he gave up on everything he had and returned to the ranks of ordinary people. But one day, Kismet, a mystical game created by the National Research and Development had appeared.

Enigmatic hands, spectral frame, and one cunning strike just like the swing of the Grim Reaper. The Supreme Assassin takes on the mystical world, and how his legendary tales sets off, progressively ascending the altar to becoming the best.

- Description from Novelupdates

I became a professor in a game by accident. To make matters worse, I even messed up the difficulty settings. Now, I’m stuck playing on Hell Mode. A world on the brink of war with the Demon King. An Assassin Department where mu*der is legal… as long as you aren’t caught. I thought I’d have to claw my way through just to survive in this wretched place, and that was the case at first. But nowadays… “No matter how hard I try, I can’t be like you, Professor… How do you do it?” “Please… become our god.” “What do you know? What is it you know? Why do you make me want to live…?” One by one, everyone at the academy began to obsess over me.

The whole world mutated. Mysterious resurrections happened in real life. The Tribulation descended.

Thousands of races coexist, where the sword and Magic shine together, the Human Race, Sea Race, Elves, Dwarfs, Orcs ... all rush to unfold the light of civilization, composing their epic tragedies!(A Lord's Farming Tale)