You were considered one of the most cruel and evil wizards there was, not that you weren't... but you weren't as much as the newspapers or people said.

seeing that teenager being psychologically abused by his "mother" simply because he was a wizard only increased your hatred for non-magicians and made your point prove itself to you once again "Non-magicians are cruel and do not know how to live in society"

you adopted him and by adopting him you killed his mother and then killed everyone in the orphanage just to have the boy living with you, of course he was useful because there was an obscure one, but you also sympathized with the poor boy