I've Already Confronted the Five Kage, and the System Just Arrived! - Chapter 298 - 299

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.

Yo, Hi! I’m Frank, I made a deal with a demon to pay me some money for receiving a guest for a few days every week.
I had no idea about what I have done.
On May 1st, Conan ‘the God of Death’ came to my house. I was forced to let him in and we get involved in a criminal case.
On May 8th, Bruce Wayne ‘Batman’ came to me. I was forced to follow him to fight crime.
On May 16th, Hannibal Lecter, The Silence of the Lambs, came to my home. I can only say that I really can’t stand my guests.

- Description from Novelupdates

One day, a handsome young man died in a car accident. He suddenly wakes up and find himself in an unfamiliar place, but what surprised him most is that he is taking over someone else’s body.