The Tragedy of a Villainess is a Manga/Manhwa/Manhua in (English/Raw) language, Fantasy series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

The social outcast, Seria, had changed.
Seria Shuteren, the vile woman who had everyone trembling with fear at her feet, was now calm.

Truthfully, the woman had not just changed, she was a completely different person.
Realizing she had possessed the wicked woman's body in this romance novel, she decided to live on the low, having a hunch about the future.

She would end those dreadful habits of Seria, avoiding her death by decapitation at the hands of Kalis, the sub male lead.