The Heroine is My Stepsister, and I'm her Final Boss - Chapter 109: I’m Sorry

Sano Yuji, a black company employee, is summoned to another world while finishing his work at home. His profession in the other world, a Monster Tamer, is considered a job that makes it difficult to become an adventurer. However, thanks to some slimes he met, which read several magical books, he gained magical powers and the second profession, Sage. Yuji acquired overwhelming power, but is he conscious of his strength? Blindly becoming unparalleled and strongest in the world!

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

Following her attempted assassination, Fatima found herself amidst a meticulously staged slave auction orchestrated by her mysterious rescuers in the capital city of a prospective ally empire. Now a slave of the Kartier Duchy, her life as a princess seems far behind her as she spends her days toiling the farms under the scorching sun. Just when all hopes seem to be lost, Fatima’s painful days eased upon meeting the strikingly handsome heir of the Kartier duchy along with his cold and seemingly gruff knight. Will she ever overcome the shackles of slavery and return home to reclaim her title or will spend the rest of her life enduring the cruel treatments of the duchess? Torn between a charming heir and a dubious knight as her potential escape routes, which hand will she grasp?