I think u can look at it like this: the heroine is a pick me. She flocks around men acting all clueless and the ‘villainess’ is just a distraught gf that hates the pick me. That’s y the personality change was 180.
Based on the novel, they were genuinely good people. That’s the issue with novels that try and antagonize OGMCs. It’s either she’s perfect and becomes bad when she doesn’t get attention, which is random and out of nowhere and overdone, or they randomly have the OGMC randomly become a bad person.
Yeah just find a guy that actually cherishes the villain. Leave the OGMC with their own happy ending
I get wanting to make the heroine into the villain but her personality change is just a 180 that makes little sense. Her sister I can at least understand.