King Mickey in KHII
The ruler of Disney Castle, King Mickey left his world when the Heartless began to attack. While he had Donald and Goofy find and protect the Keyblade Master, Mickey was on a mission of his own. In Kingdom Hearts: Chain of Memories and Kingdom Hearts II, he returns and plays a bigger role, wielding the Keyblade of the dark realm. While he knows of Riku's whereabouts, he has promised Riku that he will not say anything to Sora. In certain battles in Kingdom Hearts II, if Sora and his friends are defeated, King Mickey will step out to fight in Sora's place until he is defeated or resurrects Sora.