A Hentai System in the World of Danmachi - Chapter 8 - 7 - First time inside the dungeon.

When the apocalypse’s greatest villain self-detonated to destroy the world, Shen Qingjia died and was reborn a month after Doomsday. No power, no gold finger, no space, no way to gather food, just opened her eyes and not long after has to face fierce zombies!! What kind of non-mainstream rebirth is this ah?!

Escaping, she met a cute girl with a beautiful voice but found that she was the villain who killed everyone. For the sake of the peaceful and sustainable development of all mankind and her own safety, Shen Qingjia decided… to relentlessly reform (fall down with) her! !

Shen Qingjia, “What you want to do?! I don’t like girls… Don’t suddenly rush over!… So soft, I won’t accept, ah ah!!!”

- Description from Novelupdates

She, the tribe leader of the Miaojiang witch tribe, was reborn as a pitiful little girl that everyone could bully.

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

I intervene in all events of the game. And take it away.