City of Desire - Chapter 16: Merchant Guild II

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

Fate had never been kind to Ji Ning. Wracked by illnesses and infirm his entire life on Earth, Ji Ning knew early on that he would die as a teenager. What he didn’t know was that there really was such a thing as life after death and that the multiverse was a far larger place than he thought.

A lucky twist of fate meant that Ji Ning was reborn into a world of Immortals and monsters, of Ki Refiners and powerful Fiendgods, a world where Dynasties lasted for millions of years. A world which is both greater… and yet also smaller… than he ever could imagine. He would have the opportunity to join them, and in this life, Ji Ning swore to himself, he would never let himself be weak again! The Era he was born into was a Desolate one, but Ji Ning would make it his era.

An ordinary (?) grandfather, Choi Chuntaek. In an effort to protect his granddaughter, he started the virtual reality game 'Arkstar.'

Then... he accidentally obtained a legendary class?