Shiki is a major antagonist of the manga Black Cat and its anime adaptation. She is one of the few surviving Tao Masters from the "other continent" of Yamto, who master the mystical art of the Tao. Shiki and her friend and fellow Tao Master Maro want to spread the use of Tao in the entire world. Shiki is the second-in-command of the Apostles of Star and one of Creed's closest advisors but she ultimately learns that she and Creed do not have the same goals in mind.
It must be noted that Shiki is a woman in the original Japanese manga but that she was made into a male character in several Occidental translations as well as in the anime adaptation. This may be due to the fact that her true gender remains unknown until she takes off her mask.