she has to if she really wants to use people. you can't use people without understanding their feelings at all. feelings most of the time does affect people's actions and make people do dumb shit. that is the point of being human. does she really forget how human works?! really? if that is the case, she should have given up on the revenge in the first place.
yeas if she wants revenge she should have just killed him herself instead of going around the main problem and ruin/using other people so they will do her revenge for her. it just dumb at this point. Yes, she has to understand human feelings, again if she wants to use people she has to get them to some degree! it does not mean she has to have them in herself, but understating them is important! that is why he never listens to her in the first place.
"since when did Dylan slip through my grasp?" Charlize my darling, the moment you told him to be obsessive with you is the moment you lost your grasp with him cause you never had any real grasp with him! he had human feelings that it seems you forgot how to do and what they even are anymore.
so the moment she forgets what is human feelings are is the moment her plan for revenge failed. also, I don't get how she can be so naive to think Dylan won't be cruel has this since she personally supported and encouraged him to be a dictator all those years! what did she expect from him again? that he would be a nice tool and let her use him all his life and will be nice and kind? naive. well, at least now she knows that her way of doing things is dumb to not consider humans' feelings at all.