MTL - Chapter One of the Night - Chapter 157 men's public enemy

After all, transmigrators of this era were no simple matter. Some became slimes, others turned into treasure chest monsters, and some were even reduced to mere skull--such things were all commonplace.It was nothing more than playing a villain, Shiayar didn't care. Wasn't it only natural to pay some price to become stronger?[Destined Great Villain System][“Let this world feel the agony!”][Newcomer Mission: Let the young and naive Grand Duke's daughter of the Azure Garden Dukedom, Miss Silvia, experience the betrayal of her loved ones and, amidst the pain and despair, complete her transformation and rebirth.]

It was only after Su Yayan's death that she realized that she was a malicious cannon fodder female character who became a scapegoat in a Mary Sue story.

Lin Xiao Ci transmigrated! Her identity is a female villain in a novel in the ancient times. In order to get close to the male lead, her character has walked the path of seeking death. She decided to stay away from the male lead and his family, cherishing her life. Speedily, she prepared divorce papers and delivered to the male lead who had been set up by the original villain to marry her. “Husband, I would like to turn over a new leaf. In the past I have used you and I have wronged you. Now, I will return you your freedom.” The man snatched and tore the divorce papers into pieces, and fiercely said “Dream on!”

- Description from Novelupdates

A girl who calls herself a demon appeared before a timid student named Fumio Kijima. The girl claims to be a campaign girl from the demon world and she gives him the ability to “summon a room” from nothing but thin air.

At first he doesn’t abuse his power and uses it as a convenient ability in his every day life. But one day he is bullied by his classmates under a false pretext and is made to suffer. In the past he would have wallowed in misery and cried himself to sleep, but now he had a power to call upon.

“I will make them regret it!”

Using his powers to summon his “room”, he begins his era of confinement and brainwashing to achieve his goals.