Yen Sid

Yen Sid is a powerful sorcerer introduced in Kingdom Hearts II, and originally taken from the "The Sorcerer's Apprentice" short in the Disney film Fantasia. He is a retired Keyblade Master, renowned for his wisdom and command over the arts of magic. Although he is no longer an active Keyblade Master, he still keeps a close watch on the balance between light and darkness. He was once Mickey Mouse and Oswald the Lucky Rabbit's master, and taught him everything he knows of magic and the Keyblade.