I was a half blood growing up in a muggle family and it gave me insight as to how useless and worthless muggles are. They are ignorant and useless as they do not have any gifts like us. When I was put into Slytherine it made me realise how stupid muggles are and their filthy little mudbloods. Granted the dark lord may no longer be around but many of his followers still believe in his cause, I included, and we are still the Death Eaters you should fear. Only the pure bloods should survive.
After several long hard years at Hogwarts before becoming expelled, I liked to experiment and found a way to become an animagus. A black raven that watches other people finding their weaknesses. I was expelled from Hogwarts due to the fact I tormented students and teachers, putting curses on them when they bugged me and seriously injuring them when they annoyed me.