Yen Sid is a powerful sorcerer. First appearing in Fantasia, he would serve as Mickey Mouse's wise and serious master, which contrasted with Mickey's playful nature. Even though his appearance and attitude are very stern, Yen Sid is very kind and truly believes in Mickey, wanting him to learn and grow. In the Kingdom Hearts series of video games, Yen Sid takes a more prominent role as a retired Keyblade Master. Despite the slight change in his role, his personality is unaltered, and he provides words of wisdom to Sora, Mickey, and many Keyblade wielders.