I also hate her a little bro, but she is necessary for the plot, even if that girl is a damn Yandeer/Nymphomaniac, as strange as it may seem many people love that kind of girl, but you have to respect those opinions.
Honestly she's not giving me yandere vibes, more like just a shitty person that gets off to rape and blackmail, she's a freak and not in a good way, someone that literally creates fake friendships just to get off at betraying them, she is a piece of shit backstabbing bitch that should be laid out and permanently paralyzed from the neck down so she can never masturbate again, then they should put her in sensory deprivation chamber with only a IV drip that just gives her water and leave her there to go insane with her own mind as she slowly starves...