Classroom of elite x demon emotionless reader

Y/n was just a normal child at the time until child y/n had touched a necklace and wore it but when y/n woke up the next day she had fangs and claws, but when your parents found out that you had claws and fangs they sent you away to make you a science experiments( I think that's what you call it) and when you got to the place your parents sent you, you saw a woman named Sae chabashira, she was so nice and kind to you she would spend all her time just to stay with you, until one day you turned 16 and sae chabashira welcomed you into a classroom.