When I saw the Heartless bosses for Union X based off of Kefka and Gilgamesh, I got the idea to make a Heartless based off of the Hex Maniac from Pokémon (Gen 3 to be specific).
Description: This is a tricky Heartless that uses a wide range of both offensive and defensive magic attacks; she can chuck the two orbs in her hands, create a shield that confuses you on contact, and cast a majority of the normal Elemental spells. Holy is the only magic spell that can be used against her. She can also send in Yellow Operas and Pink Concertos for backup.
Worlds found: Radiant Garden, Twilight Town, Kingdom of Corona, Agrabah, Olympus (Coliseum and Underdrome), The World that Never Was