I Raised the Demon Queen (Now She Won't Leave Me Alone) - Chapter 83 : Locket and Letters

Being the author of the breakout novel, Gates of The Primordials, Jarren Fletcher did not care about the constant critiques claiming he had a habit of treating extra characters as mere plot devices, creating and then dumping them once they’d served their purpose.To Jarren, it didn’t matter. Extras were just that—extras. All that mattered was the main character.But Jarren never expected to wake up in his own story, reincarnated as one of the meaningless, disposable extra characters, Deremiah Morcant—a coward who took his own life to escape the perilous challenges of the Gate Trials.Now, Jarren has to face those deadly challenges himself in the body of a weak, insignificant extra. He must find a way to survive in the rules of the dangerous world he had created, whilst also trying to save it.But time is running out. The next Wave is coming, and so are the paragons.

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

When Li Shen’s second personality acts out, her consciousness is sent to a strange place called Split Zone No.13. She is then informed that she can only return home after unraveling the truth.

Just like how everyone adored heroes in their childhood, a certain young man adored those powers hidden in shadows. After hiding his strength and living the mediocre life of a mob character by day while undergoing frenzied training by night, he finally reincarnates into a different world and gains ultimate power. The young man who is only playing at being a power in the shadows, his misunderstanding subordinates, and a giant organization in the shadows that gets trampled…. This is the story of a young boy who had adored powers in shadows possibly eventually reigning over the world of shadows in another world.