According to the raws and Google translate, after Eli has her engagement to the prince voided, she goes off the deep end. She returns home to her drunken depressed farther and convinces him that all they need to do to fix everything is kidnap Leslie again and put her back in the black fire so she can inherit the darkness power. I'm not sure what happens next since they haven't gotten to that part yet but I honestly don't think that with how spoiled Eli is at her core from constantly being viewed as the favorite sister and then being brainwashed into believing she'll attain great things if she gets Leslie's power of darkness, that unless something really drastic happens to shock her very core beliefs then she's not gonna be able to redeem herself. Honestly, because she doesn't see herself as having done anything wrong and yet everything she feels that she rightly deserves is being taken away from her, that whole mindset of hers needs to be fixed or she'll never progress as a character. We'll see though.