The Blueprint Prince - Chapter 4 - 3: The ROI of Ruthlessness

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

She had a dream: the world was brimming with light. Family. School. Friends. Trains. Buses. Movies. Books. In that world of light, she grew into adulthood… and at the very end, in a white room, she fell into darkness. She awoke from the dream to find that she had become a demon. In the demon world, she lived a carefree life until she encountered a powerful being.

Seventeen-year-old Hajime Nagumo is your average, everyday otaku. However, his simple life of pulling all-nighters and sleeping in school is suddenly turned upside down when he, along with the rest of his class, is summoned to a fantasy world!

They’re treated like heroes and tasked with the duty of saving the human race from utter extinction.

But what should have been any otaku’s wet dream quickly turns into Hajime’s nightmare? While the rest of his class are blessed with godlike powers, Hajime’s job, Synergist, only has a single transmutation skill. Ridiculed and bullied by his classmates for being weak, he soon finds himself in despair.

Will he be able to survive in this dangerous world of monsters and demons with only a glorified blacksmith’s level of strength?

In the end-French era, after countless calamities, the era of cultivation is coming to an end. The last combination of air transportation and evolution has evolved into the treasure board, which was obtained by the last practitioner in the end-French era, which opened up a legend of wandering heavens.

- Description from Uukanshu