MTL - Fox in the Penalty Area - Chapter 101 in the plan

What if you received a divine artifact?What if yours was the strongest soul in the world?What would you do with the power to simulate anything, even an entire solar system?Follow Jack as he learns how to use his new gift, makes new friends, dominates the technology sector, travels to the stars, and so much more.There will be a harem, but Jack will not be snatching up every girl that smiles at him.There will be R18, but it won't be the dominant theme.There will be robots, and nanotech, and so much more.And maybe a face or two will get slapped along the way.

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 villainess sees herself executed in front of a large crowd by the order of the emperor (her husband and the one she loves). However in the next moment after her death, she is back in the past. Monique is sent back into the past because of her brutal memories of her previous life with a prince who was engaged due to their similar age. When Empress grew and looked at the past, she killed her emotions to live as an Empress and remained one emotion, that was sickening affliction. Where in her next life, she made new connections in order to avoid getting executed again…

A man is reborn into the world of Avatar: The Last Air Bender as a waterbender from Katara's tribe. Best of all, he was the same age as her, and he had a system with him to help.He knows the future and a system that lets him continuously get stronger by completing quests or long-term missions, as well as giving him the ability to copy abilities from others for himself. He will become invincible in the world of Avatar, even more so than the Avatar himself.