Manga wo Yomeru Ore ga Sekai Saikyou ~Yometachi to Sugosu Ki mama na Seikatsu~ - sChapter 35: Dragon Race

In a world ravaged by fiend beasts and spatial rifts, humans fight back using “”Soul Contracts”” to tame these creatures, turning them into protective spirit animals. Amidst this chaos, Zhou Mu, born with inadequate soul intensity and physical prowess, struggles to become an esteemed Animal Whisperer.With only a low-tier grass snake as his spirit animal and limited chances to pass the Whisperer’s test, Zhou Mu’s future looks bleak. However, an unexpected twist comes with the discovery of a mysterious system that allows him to trade personal attributes for power. As he navigates this new potential, Zhou Mu faces the challenge of overcoming his limitations and rising to power in a world where strength determines one’s fate.

Su Ran, a music prodigy, woke up transmigrated into a book.

At that point in time, the main story arc in the book had already been completed. As a villainess female supporting character, not only did she need to take over the original owner’s pitiful life in poverty, she also gained an instant son right at his rebellious period.

Ten or so more years from then, the son would turn into a twisted, evil villain. He would appear in one of the extra chapters to pick on the male and female lead’s children.

***

Su Ran: Son, you shouldn’t be too outstanding.
Su Han: Why not?
Su Ran: ’cause you will be killed.

Su Ran: Son, would you like to learn music from me and become a zen, little fairy boy who only needs to drink dew.
Su Han: No, I want to go into business so I can support you.

- Description from Novelupdates

The old man pointed to the flower-like woman and said, “Call her mother from now on.” He then pointed to a flower-bud-like girl and said, “This is your sister.”

My younger sister was not cute.

She was arrogant, taciturn and weird, but she knew how to please our parents.

She was two-faced and deceitful, but it seemed like she only treated me that way.

I cared for her, tried to please her as much as I can, but she still disliked me.

Until one day, I found out her secret, our relationship began to get a little bit weird…

- Description from Novelupdates

Roy’s life was nothing special. The only thing commendable was the last few moments when he saved a mother and her child from a drunk driver.
…
It’s really an egg! Damn it, what kind of monster have I become? Did I fall into Hell instead of making it to Heaven??
Join Roy as he ventures through various worlds with the Custom Made Demon King System—a system that allows Roy to draw anything he can imagine and create it through exchanging souls!