Vanitas

Vanitas (voiced by Haley Joel Osment) is Master Xehanort's evil apprentice and is the darkness from Ventus's heart. Vanitas also is the source of the Unversed. Most of the time, he is seen with a mask on, but without it, he looks exactly like Sora. His plot was to make Ventus strong enough so that they would merge and create a powerful weapon called the χ -blade. Even though he was successful, he was defeated by Aqua and King Mickey Mouse in a physical battle, and by Ventus in a metaphysical battle.