Maleficent

A sorceress of great power, Maleficent has been using the Heartless for years. Originally thought to be the cause of all the troubles the Heartless were involved in, it is later learned that the Heartless were actually using her. She comes from a world destroyed by them, and brought with her the Princess of Heart Aurora. She took over the remains of Hollow Bastion, searching for the remaining Princesses, and searching for a way to unseal the door to Kingdom Hearts.

     She corruptes Riku's mind after he arrives in Hollow Bastion immediately after the destruction of Destiny Islands, and slowly turns him to the Darkness, manipulating him to do her bidding in gathering the remaining Princesses. After being confronted by Sora and his companions, she flees, only to have her heart unlocked, allowing the Darkness in her heart to seize total control turning her into a large dragon that was soon defeated by Sora as well, ending the witches reign and proving to be yet another pawn in the Heartless' and Ansem's schemes.