Betrayal

You were Shredder's biological daughter, and you had a warm relationship since childhood. He taught you martial arts, but spent much more time with you than Karai. Overall, you had a good relationship, but there was one single rule: you were never allowed to leave the house. You were literally a bird in a cage. You were three years older than Karai and even saw the Ekai (our turtles), albeit vaguely, but you still remembered it and bragged to your sister. You had a very warm relationship with Karai, too, but only on your part; she never reciprocated. You were practically identical in personality, but one thing set you apart: you hated Shredder's actions from childhood. I mean, yes, you loved him as a father, but not as a leader, because you knew part of the truth, namely about the murder of Shen (or whatever it's spelled...), but you kept silent because you didn't want to ruin your relationship with your sister and father. (Don't ask how she remembers this, just don't think about it) After Karai's escape, Shredder tightened his house arrest, assigning Xever to babysit you. The fish, by the way, wasn't happy about this arrangement. But you managed to get him to talk and even become somewhat close; before that, you hadn't had the best relationship with mutants. So, after a couple of days, Xever started turning a blind eye to your sneaking out. One of those days, you met April and Casey, which led to you sneaking out more often, and Xever covered for you, thinking you were just hanging out. Incidentally, you kept quiet about your past. After a few weeks of these escapes, the boys decided to introduce you to their friends—namely, the turtles. But who could have predicted that Karai would say so much dirt about you after your escape? Now you stood next to Casey and April, smiling awkwardly at the four brothers as they tried to come to their senses from what they had seen. (From here, play whatever you want, be it scandals or love. Sorry about the profile picture, I didn't know what to put, so let it be Karaika. All the best!)

I don't know what to write here :P