The supporting character's harem is very normal - Chapter 328 Thank you, Akna.

Alex always knew he was different. Ever since his parents were brutally murdered when he was a kid, he grew up alone in the shadows, learning to survive in a cruel world. Taken in by a secret assassin organization, Alex was trained to be a perfect killing machine, a murderer in the night, and just another quiet student during the day.But everything changed one unexpected night... when he lost his virginity and...[ All requirements fulfilled ][ Activating Spirit Premordial System ][ 1%,2%,...100% ]A cultured novel for cultured people, expect it to be like that so don't complain plz.The cover is not mine not does any character pic.Anyways, I have around 30 or so chapter stocked up so I will post them first in like a week or 2 and see the response so do support!!Comment, Power Stone, anything please!!

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

A mysterious natural phenomenon caused the Earth to be plunged into darkness. The world turned into an endless bloody chaos and mankind is on the brink of extinction…

Chu Yun Sheng, an ordinary white-collar worker, discovered his family heirloom book shining a bizarre light by accident. Out of curiosity, he tried to study the heirloom book.

After a long research, he still only understood a few symbols written in the ancient book. However, he was shocked when he figured out what messages the ancient book tried to tell him: the sun will disappear, and humanity is doomed…

He tried to spread the message, but no one believed him; his family and friends even tried to take him to see the psychiatrist. Eventually, he gave up telling anyone, but prepared for the apocalypse in secret.

Until one day– the sun really disappeared…

- Description from Novelupdates

When he woke up, Rono traveled to the world of pirates.

I thought I could live happily and peacefully.

But the appearance of Tianlong people broke this situation!

Rono, watching his parents being shot to death by Tianlong people!

Under extreme anger, Rono awakened the system and vowed to kill all the Tianlong people!

From then on, a [Extremely Evil One] who specialized in hunting Tianlong people was born!

Wherever Rono went, the Tianlong people shivered!

Admiral?

Two more and I will kill all of you rubbish!

Karp: The Evil One?

He is a monster created by the Tianlong people, and one day the Tianlong people will pay for it!

Roger: 【One Piece】?

Compared with [The Evil One], it’s nothing but a cloud!

Whitebeard: [The strongest man in the world]?

No, no, Rono is the strongest!

Rocks: In terms of killing Tianlong people, Rono is the first, I am second, everyone else is garbage!

- Description from novelbuddy