I Reincarnated into an Otome Game as a Villainess With Only Destruction Flags… - Volume 3 Chapter 2 — Everyone’s Respective School Festival Part I

This is a world where humans, demons and mysterious beasts coexist.

Humans cultivate mysterious qi. Demons cultivate corporeal bodies. Mysterious beasts cultivate soul perception.

A legend says that in the middle of an endless rainforest, there are extremely powerful existences; they are called demon kings.

Some demon kings have a tyrannical corporeal body, some are experts in illusions.
Some demon kings are proficient in magic, some can even move mountains.
Some demon kings are able to sense things thousands of miles away.

These demon kings rarely appear in the human world. Even if they emerge in the human world, they would reincarnate in human form; assimilating with mankind while seeking to breakthrough realms…

- Description from Novelupdates

After accidentally falling, she actually finds herself bound to a Second Female Lead Counter Attacking System!

Haruto Hayase was a normal high school boy in his third year, living a quiet life until his younger sister, Haruka Hayase, joined the same school. Haruka’s beauty and charm made her the center of attention, quickly becoming the school’s prima donna. But when a notorious gang leader set his sights on her, he did everything in his power to protect her—only to fail tragically. Haruka was brutally assaulted and tortured, and Haruto himself suffered an agonizing death. However, in a twist of fate, Haruto is given a second chance, waking up a year before the events that shattered his life. Armed with the mysterious ‘Debauchery System Slave’, he vows to exact revenge on those responsible. This time, he will use his newfound powers of the system and charm to seduce the loved ones of his enemies. From their mothers, sisters, and lovers to their closest friends, Haruto will make them his. His enemies will suffer as he steals what they hold dearest, ensuring their downfall in the most devastating way possible.

This is not your usual isekai novel. it has my unique world background, unique power system and i am trying it make it a unique experience for every reader. :)

Athan, a 16-year-old boy, lived until he was killed for a stupid reason. (stupid reason & more in the prologue:v)

But it seems that fate had stored different things for him as after death as he transmigrated in the magical world inside a dead body of a boy with the same name and same facial features as him.

He also found out that a mysterious black whirlpool seemed to be inside him.

Was someone responsible for his transmigration? if so then who? and why? or was it pure coincidence that he got a new chance at life?