MTL - The Problem with Marrying Rich: Out of the Way, Ex - Chapter 1544 : Daughter-in-law she wants

When an alien ambassador crash-lands in Tim's backyard and demands, 'Take me to your leader,' the 12-year-old does what any kid would do: he points to himself and says, 'That’s me. I’m the King of Earth.'Now, thanks to a hastily signed treaty (and a promise to hand over Jupiter), Tim’s got an armory of world-ending alien tech, an invulnerable Planetary Base in his backyard treehouse, and one tiny problem: nobody told him ruling a planet would be this hard. Between conquering Earth, fending off hostile fleets, outsmarting intergalactic bureaucrats, and explaining his absences to his Trekkie dad, Tim’s in way over his head. But if he can’t bluff his way through alien diplomacy fast, humanity might end up as collateral damage.“King of All I Survey” is a fun, heart-pounding sci-fi adventure where one kid’s lie decides the fate of Earth—and homework is nothing compared to intergalactic war.

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

She, a renowned assassin of the 21st century, actually crossed over to become Su Manor’s most useless good-for-nothing Fourth Miss.

Once, because of a pair of purple eyes he was scorned. He is a wangye known across the land, cold and bloodthirsty, looking disdainfully upon the world.