Mystic Defender (JP: Kujaku Ou 2: Geneijou, or "Peacock King 2: Castle of Illusion") is a side-scrolling action-platformer from Sega and the continuation of SpellCaster for the Master System (originally called Kujaku Ou).
Both games are based on the manga and anime of the same name, also known as Spirit Warrior, by Makoto Ogino. Its story concerns the titular monk, Kujaku (Peacock), who is the reincarnation of various important religious figures, and part of organization tasked to take down demonic forces that threaten the world of mankind. The plot of Kujaku Ou 2 concerns the return of warlord Nobunaga Oda in a new demonic form that Kujaku and friends need to destroy, especially after he kidnaps their friend Ashura. In the Mystic Defender version of the game, the story and characters have been changed: the magic-user Joe Yamato travels to the castle of Zareth, the underling of King Zao, to rescue Alexandra, the daughter of "the supreme deity."
The game has the protagonist working his way through each level, taking on various foes and obstacles in 2D platforming levels. Rather than use weapons, Kujaku/Joe has an array of powerful spells he can use, gaining new spells as the game continues. These spells have different ranges and effects, adding some versatility to the player's repertoire.