Shikkaku Mon no Saikyou Kenja~ Sekai Saikyou no Kenja ga Sarani Tsuyoku Naru Tameni Tenseishimashita~ - Chapter 237 Strongest Sage, Down the Dungeon

Immediately after Gu Changge realized he had transgressed into a fantasy world, the world’s protagonist, and fortune’s chosen, vowed to take revenge on him. Envied by all, he not only has the female lead head over heels for him but he’s also treated as a distinguished guest wherever he goes. Fortunately, Gu Changge’s prestige and power are superior to everyone else’s, so shouldn’t it be easy to trample on a mere fortune’s chosen?

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

Li Feng found himself in a dangerous demonic sect where he could be killed at any moment. But he was worried as he had his ultimate upgradation system.Blood Essence Pill -> Blood Origin PillTurtle Breathing Mantra -> Xuanwu's Great IsolationPhantom Spirit Fox -> Nine Tailed Celestial FoxJust like that, Li Feng was confident that he would be able to become stronger at a very fast pace and would be able to survive in this dangerous demonic sect. Not only that but as his parents were killed by some of the disciples of this demonic sect, he was also going to take his revenge on them. With his system's assistance, Li Feng was confident to reach the pinnacle of cultivation.

In the tenth year after the new era, the world finally came to an end. Zhang Mu truefully waited for his death, but unexpectedly found that he had returned to ten years ago. With his memory about the future, he swore that he would change the calamitous history, saving the earth from being destroyed! Walking dead, zergs, evolvers, and various mutated animals… nothing can stop him! The first step is to retrieve his identity as an era merchant , then find all the treasures he can remember to enhance himself!