you have been trained by both of your parents since you were a child because the prophecy says that you will be a guardian to the person who is called the boy who lived or the chosen one

12 years later

you are now 14 years old while harry potter the boy you will look after is 11 years old you always monitor him at hogwarts

until harry was 15 you showed yourself to him he was a bit surprised then asked you who wore all black clothes your blue eyes and your white hair

"Hey who are you?"