[A spiteful, ruthless villainess who takes revenge for every slight / a saintly man at first, then a dark and twisted nonhuman ghost][Mutually faithful][Love and hate]
Jiang Yueye is ugly and ill-mannered. Just standing there is enough to make people dislike her. She's a notorious gutter rat, someone anyone can kick around.
By contrast, the girl who shares her name is beautiful, gets good grades, is popular, and comes from a prestigious family.
She's practically Jiang Yueye's opposite.
Later, Jiang Yueye learns she's the disposable foil in a book, there to make the heroine's pure goodness shine.
And when the story ends, she's destined to die at the hands of one of the heroine's admirers.
Gazing at the heroine, who is surrounded by admirers, Jiang Yueye's eyes turn scornful as envy boils inside her, tormenting her over and over.
Then someone claiming to be a Good Luck System appears, and everything changes.
Those who hate her are ruined. Those who look down on her, she crushes mercilessly beneath her foot. The people who bullied her end up missing or dead.
With the System's help, she uses every means at her disposal to claim beauty, academic success, wealth, and fame. Yet the heroine above her still shines like a blazing sun,
making Jiang Yueye seem even more despicable by comparison.
On her birthday, Jiang Yueye wishes for the heroine to disappear forever.
Later, her wish comes true. The heroine jumps from a tall building right in front of her, hot, wet liquid splashing all over Jiang Yueye's face.
The person everyone hated is finally gone. Jiang Yueye throws parties for three days straight to celebrate, but after that, something seems to change.
She wakes up one day to mysterious bruises on her limbs.
At midnight, footsteps sound out of nowhere in the living room.
And...
It seems that loathsome thing has come back.
(All main characters are adults.)
"I've seen plenty of hell. There's nothing to be afraid of."
The Astrologer of Hell
I like this book