Bad kitty, but it's very cat-like as she is very selfish, she want yuuki for herself and no one else but she is doing it for yuuki protection and nothing else, there cant be 2 people with powers running out of control, yuuki saved her, so she will prioriteze his protection above all.
I can confirm the selfishnes, My cat doesnt like any other pet animal to get near me, she drives them away then purrs me like nothing happened.