A Journey That Changed The World. - Chapter 9 Level Hunting.

After self-sacrificing, Yuri transmigrates from an apocalyptic to an interstellar era, inhabiting a disabled girl's body. She enters a joint marriage with a similarly disabled SSS-tier alpha, gaining a share in an ore planet. Determined to help her husband regain leg function and reclaim his SSS-rank, their journey together unfolds.

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

…but it seems pretty doable.

After all the things that he had done in his life, Alex realized that it was already his time to die.