The Cursed Seal of Reflection (自省の呪印, Jisei no Juin) is a Juinjutsu inscribed unto Mukūrō ever since he was young in order to control the extent of his powers. However, it is only in recent years, through tutelage underneath Kazuhide and, to a certain extent, Akiya, that he has managed to grasp the nature of the seal and use it to his advantage.