Will of chaos - Chapter 1792: Cap 1790: Greetings, Bringer of Chaos...

A broken man who ended his own life finds himself reincarnated into the game he used to play. However, instead of becoming the protagonist or a powerful antagonist, fate places him in the role of a minor villain—a mere stepping stone for the protagonist in the game's first arc.

A Federation Colonel with abnormal thoughts was locked in a dark room and met a little looney.

“Your whole body emits a scent that I dread (covet) and fear (desire).”

A frigid Colonel X little looney roommate: A sweet story of interstellar travel

- Description from Novelupdates

Lachlan, once a victim of deceit and betrayal, wakes up to find himself back in his high school days, just before his life took a dark turn.With a newfound system that grants him immense knowledge and skills, Lachlan vows to change his fate and protect his love, Julius. As he navigates through old rivalries and new opportunities, will Lachlan succeed in rewriting his destiny and exposing those who wronged him?

Beings that create and control monsters and demons, beings that build and reign over malicious labyrinths, the chosen individuals to possess an overwhelming Unique Skill… They are the Demon Lords.