Regressor Instruction Manual - Chapter 26: Item (1)

One day he suddenly found himself in hell.
All he had was the desire to live and a predation ability.
From the first to the ninth thousand circles of hell, he absorbed dozens, hundreds of thousands of demons.
Even the seven great dukes of hell bowed down before him.

– Why would you wish to go back? Doesn’t his highness have everything that’s in Hell?
– What do I have?

Nothing to eat, nothing to enjoy!
The only things in Hell are the barren lands and terrible demons!

“I’m going back.”

After ten thousand years he returns to Earth.

A recurring nightmare afflicted Khan's nights since the Second Impact. His dreams replayed the scenes of the crash of the Nak's spaceship, an alien race that the humans had defeated five hundred years ago.

Will, a seasoned game designer, found himself reincarnated as the disposable villain in a cliché “kicked out of the party” novel. Faced with his inevitable tragic fate, he had one ambitious dream: to turn the pitiful “losers” from the protagonist’s harem into terrifying blackened bosses who would torment the protagonist!He taught the timid and cowardly wolf-girl maid to imprison the one she loves forever by her side.He trained the tsundere, sharp-tongued loli witch to make her beloved see only her in his eyes.He guided the cold and clueless half-elf princess to use…—

"When will people understand.... I'm only half insane?"