Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 15 - 15-18. Intermission

Cho Ryu Hyang was good at math from a young age. When he enrolled into the The Theoretical Maths and Martial Arts School, the teacher, Jo Gi Chun, recognized Cho Ryu Hyang’s talent immediately and took him in.

Ye Fan accidentally obtained a billion crystal technology system, and since then, he has become out of control.

Android: You do n’t even have a mobile phone system. I want to make it impossible for you all!
Ye Fan: Sorry, I researched it out, it seems to be more powerful than yours!
BMW Benz: Our engines are famous all over the world!
Ye Fan: Sorry, I do n’t have an engine, I only have magnetic levitation, and the speed is only a few times that of yours. Do n’t worry, take your time!
…
Enemy: Is he still human?
Who can stop this!

- Description from Qidian

Male lead quick transmigration romance— originally called Soul Pawn Shop.

Hell’s ruler Xie Fei travelled through three thousand worlds to guide traders to redemption.

—Ding-dong! Welcome to the Soul Pawn Shop.

Note: 1V1 romance

- Description from Novelupdates

A strange event happened in Blue Star, a large number of Blue Star people were affected by a mysterious force, and their souls temporarily traveled to another world.

It’s a dark, weird world

Not only are the prices extremely high, but there are also many evil spirits quietly appearing. At the same time, various forces are fighting with each other, and the people of the lower classes are suffering.

Yang Fangben, the attending physician of the mental hospital, also traveled through a strange incident.

Fortunately, he found that he had awakened a proficiency panel.

As long as you keep refreshing your proficiency, you can improve your own realm.

He grew up secretly, with corpses piled up under his feet, and he unknowingly embarked on a path of sagehood.

- Description from novelbuddy