Mark L. Ishirau

Mark L Ishirau, also know as Doctor Ishirau, is a member of the Lev family tree. Mark specialises in defense magic and healing magic, which is why he's working as a doctor. After the age of 17, Mark found out that despite being a child of the Lev family, he's an illegitimate child of a woman who was the secret love of his father, and after Mark was born, his father took him and abandoned the woman. Since then Mark changed his family name to "Ishirau"

Mark knows that Efes is his nephew because despite Efes's records showing his name as "Efes Sonata", Mark has already met Efes when he was still a baby.