The Master is one of the most dangerous beings in the galaxy and the most dangerous person to the UGI due to his former Cipher Agent status but none knows which Cipher Agent he was. Nor does anyone knows his name.
Being a member and leader of AUREC makes him the most sought after criminal and Terrorist. Known for his leadership none has seen his face. Nor does he appear ever to anyone. The only image of him was taken during a mission by a Cipher 2 and managed to see the Master in combat armor that he is always wearing.