罪

an incomplete list of reasons utena gives anthy to distrust and despise her:

not only forgetting about her completely after making a grand promise to save her, but fixating on the occasion as a romantic promise with dios. this alone justifies the stabbing

idolizing her abuser in general while anthy knows exactly what he is. of course anthy would doubt her judgement

aspiring to be a hero with no experience of the sacrifice anthy knows deeply, wanting to save anthy without knowing that anthy made a choice to be the rose bride or why. utena didn't show her that selflessness or nobility was possible, but that somebody else would finally do it for HER

being oblivious to her own charmed position and not understanding that anthy cannot make friends the way she can, downplaying the adoration she receives from other students, pushing anthy to socialize when she doesn't want to, being unable to grasp the resentment of the black rose duelists, even her own close friend

the affection of someone who doesn't know you and lashes out for the "betrayal" of you being incested is not reliable. akio is nothing if not committed to keeping her

we remember that dios wanted to be a prince and couldn't take the burden when it wasn't just being praised and escaped from it by vilifying anthy right