Princess Crystal, most known as Crystal is young woman with long blond hair and big blue eyes. It's seen that she have healing magic, with which she heal Duke and saves his life. After that she fall in love with him. It's seen that she have promise to her teammate - Cipher, who's seem to dislike Duke because of Crystal's acts to him.
With her friends it's seen that she's serious, but with Duke she's cheerful and careful.
It's not seen much about her relationships with others.
She is friendly, careful and cheerful to him. She saved his life and maybe she have love interest to him.