i just have a theory. She might be from a parallel world like pretend ours and The Abandoned Empress is actually a novel from that universe. The girl/ saint is a fan of the book and is in love with the prince. She hates the villainess ( the white hair girl) and one day gets recreated into the book as the "protagonist" . She pretend to be nice and loving, and villainess herself without understanding Aristia situation. So she kills her. Aristia goes back into time, which is the beginning of the book and the now "villainess" the past protagonist is now the "villainess". The black hair girl still thinks the same, but now the story have changed due to Aristia choices. So yeah
Nice theory but kinda off. There's another one I've read before that Jieun's purpose was never to be Ruve's partner to begin with. She may have been a child of Vita but wasn't his destiny since it's obv he shared that with Tia. Jieun was meant to bring peace to them by being an instrumental witness against the real antagonist. So no, she didnt take the role of protagonist, she was never one and no she didn't turn into an antagonist. Her and Tia's rivalry are child's play compared to the real crimes happening.
This is not the right theory. I'm not sure if it was the novel read by her but other than that your theory is completely wrong.
I'm sorry that my theory is kinda off, I just thought that it's because in the beginning she was brought in a Korean school uniform, which meant she was a student in Korea. So I thought it had to do she was like a fan of a novel. But thank you for correcting me!
THAT MAKES SENSE?!?!! but why is she starting to become a villain though?
Oh I think she was always the villain, except at the beginning of the story, Aristia thought and words were only following the "original" story and that The black hair girl was just following the heroine words and faking it all along. However after Aristia is reborn again and went back in time, she somehow changed the story since she thinks differently now. This made the prince liking her more and the prince no longer thinking about the black hair girl. ( I also think the story changed all together because of the two new male leads)
But what about Gods voice that said she was born with Gods love??
what happened to the black haired girl that caused her to go from rose to poison ivy?