I, the Supreme Overlord, Start by Enslaving the Zerg Queen - Chapter 41: Crafting the Elixir, Another Ability of the Bloodthirsty Zerg!

When Feng Qing was born, she was sold to a couple from the mountains due to the hospital’s negligence .

I became a scientist for an evil organization.…But I’m too competent.

A campus bullying incident led Chu Feng to receive a message of Rong Yun’s suicide after ten years.

Rong Yun’s relic is a novel based on him…

At this point, he came to know that Rong Yun had always liked him.

In deep regret, Chu Feng returned back to high school.

This time, he wants to protect Rong Yun, his achievement and let him have a different life.
At first, he only wants to compensate for his mistakes, but he didn’t know when his compensation become’s true love.

- Description from Novelupdates

One day, I woke up only find out that I’d become a Demon Lord, an individual responsible for protecting a dungeon. The world I’d been spirited away to was one filled with violence. Gigantic monsters wandered through it and competed with each other each and every day for the right to survive. I had no choice but to strengthen my dungeon’s defenses in hopes of living another day—or at least that was what I’d thought. For some odd reason, I instead ended up spending my days in relaxation and bliss.