I feel you’re right when it comes to her own past enemy, but not so when it comes to the new enemy she makes : how come she doesn’t get rid of the true bad guys before making new enemies out of any little girl on her wrong side ?
- there’s not sense of proportion : many of her new enemies are still teenagers, disturbed or jealous kids that could have been turned around if she had clarified or showed a little understanding, instead of her absolute despise and wicked ways - they might not be nice, but some have serious reasons…
her cousin can really be jealous : her family is truly unfair
the illegitimate sister of her friend is very pitiful too, so yes she’s fake, but where can she stand ? Born to be mistreated and humiliated for the mischief of her parents ?
the fast food girl does turn bad out of misunderstanding and jealousy, but she could have prevented her evil fake friend from ruining her reputation instead of letting her run wild forever - in anycase, her means are weak and everything could have been prevented so many times, and why involve her family ? Whatever mistakes the girl made, was it worth extorting millions out her dad ? Ruinions their family long term partnership ?
and what about a stupid girl in a party, isn’t it out of proportion to publically humiliate her buy ruining her clothes and let her be shunned because the white lotus heroin boyfriend is the ultimate boss in small city… ? Honestly it’s a true antagonist job ?
Is she frustrated that she actually does nothing against real criminals, so she vents on small kids ?
Her legitimate revenge is not a reason to abuses anyone who offends her slightly - the mc is obtuse and self centered, everything she reproached the basketball captain could be said about her - she self righteously ruined teenagers and treated them actually worse than she does with the true bad guys that are out to murder her - and that she actually never handled until nearly 300 chapters in…
Do you really find it « normal » ?

I think the FL acts horrible in a certain [your] perspective is because she is currently taking revenge. What kind of person who comes back from the dead, and experienced hell will start acting all nice and lovable. I wouldn't be. I think her actions is pretty normal when taking revenge against those people who treated her badly. As a person, she suck shit (yeah) but she has no time to play fair when her life, friends life, families life, and love life are at stake. She can't be sure that the future has completely changed. Her life's a Bitch, she gotta harden up and be a bitch too. Cause noones gonna change her future except for her.