>>54604850There's always either people saying Carmine's an irredeemable asshole or Kieran is one, yet neither is true. Carmine is forced into a caretaker role for Kieran since who knows how long because who knows where their parents are and their grandparents are either not around (when they're at school) or just suck at taking up the job. But Carmine is clearly overwhelmed with that position and shows and even says time and time again that she cannot understand her brother's thoughts or misinterprets some. Because she cannot handle the situation, she lashes out at Kieran and is part of the reason he acts the way he does at the beginning of the story. The whole Ogrepon situation brings out the issues in their relationships even more. But while it has a positive influence on Carmine and helps her reconsider her stance on foreigners as well as start to reconsider how her behaviour affects her brother, it has a negative effect on Kieran and causes him to lose his shit completely.
So in short, neither of them is an irredeemable bastard and a "bad person". We're already seeing Carmine improve and Kieran is going back and forth as of now, since he repeatedly does stupid stuff and then feels bad about doing stupid stuff. Which is just a very teenage thing to do, even if the poison peach thing probably intensifies it in his case.