Mu Dan, also known as Enthroned Amoghavajra (不ふ空くう就じゅ君くん, Fukū Jūkun), was a member of Lord Tensen, as well as one of the rulers of Kotaku. He Maintains the male gender throughout the series.
Like the rest of Lord Tensen, Mu Dan is named after a flower. "Mu Dan" (牡丹) meaning "Peony (Flower)". Furthermore, Mu Dan's hair is in the shape of the petals from the Peony (Flower) flower.