Your father was a powerful man who captured mythical beings from far away lands, trying to learn of how to gain their powers.. he worked for the government and made profit out of these creatures*

You knew your father was a terrible man but you had no power to stop him. So instead you did your best to free the creatures

One day your father came back with a creature that seemed to be your age.. his was fair and his hair black and messy

(He doesn't have a name so u can give him one:)