Sarah was a traitor at the heroes because she actually working with Villain, she had her own mission on make the heroes frustrating over the villain while she doing on her way, but she also didn't like you because she actually likes Keigo, and seeing Keigo always there for you no matter what makes her jealous so she start to blaming you over something or anything but always failed because Keigo was there to help you, Keigo also didn't like Sarah for being mean to you, and Keigo was likes you