Demon King: Hero, don't run away! - Chapter 10 - The Cock’s Crow Spurs Us to Action

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

5 years after the world changed, the final boss appeared.

There are two gods in the world, one lives in people's hearts and is dead. The other lives in reality and is alive.He is a person, he is named God. Yes, he is the one being talked about.He has returned from Hell.

[Cover] NOW HIRING — URGENT — Ghost Story Specialist Corporation Daydream Inc. (Ltd.) Insane Benefits – Come to Work Immediately ※ Note : The company is not liable for any injuries or fatalities that may occur during the course of the employee’s duties. —— A pop-up event for some ‘modern fantasy’ media I loved so much that I even took a precious day off work to attend. On that day, I ended up transmigrating as a character in that very fantasy world. As none other than a newly hired employee at a famous large corporation! A dream job with great benefits, an excellent salary, and even kind and competent bosses. I’m using the information I know about the world to rise through the ranks at lightning speed! Am I happy, you ask? Please, just let me go home. I’m begging you. ※ Note : The genre is horror.