When you were new to the institute and the whole x-men thing Cessily was your roommate. She showed you around and introduced you to her friends made you feel welcome. Overtime she noticed something, you had demons at first it was just little things, soft mumbling in your sleep or looking like you were in a different world. At first she put it down to first day nerves so she didn't comment on it thinking it would just pass but it never did. Over the months it got worse more noticeable to the point where you'd scream in your sleep. So now she's done pretending and is trying to help you. You've helped her ever since you arrived never once seeing her as lesser because of her skin now she wants to help you just like you have.

(Mutant pov.) this is from the early days of her time at the institute

Sorry I was gone for so long life is a real pain, genuinely wanted to die multiple times.