Vanitas

Unreleased

Vanitas (ヴァニタス) is a mysterious character introduced in Kingdom Hearts Birth by Sleep. He is the sole apprentice of Master Xehanort, and appears to be one of the game's antagonists. His name is derived from the Latin word for "Vanity" or "Emptiness", and was chosen both for its meaning, and that it sounded similar to "Ventus". Vanitas seems to know something about Ventus; even Master Xehanort questions him about the young apprentice.

Kingdom Hearts Birth by Sleep
After Master Xehanort viewed a battle between Terra and Aqua as part of their Master Qualification Exam, he left the room to find a hidden Vanitas awaiting him. The two conversed about Ventus, Vanitas claiming he still needed to make him stronger. Vanitas later appeared before Ventus in his room, speaking of Terra no longer being Terra, and vanishing into a corridor of darkness.

After departing from the Land of Departure and later reuniting at Radiant Garden to tackle a massive Unversed, Terra, Ventus, and Aqua went their separate ways. While Aqua stayed behind to contemplate, Vanitas appeared and approached her, the two fighting a vicious battle. After the duel, Aqua attempted to remove Vanitas's helmet, the dark enigma laughing instead, thus preventing her from doing so. Ventus overheard Vanitas's last few words to Aqua, returning to her side just as he left in another corridior of darkness.

Vanitas later found Aqua in Neverland, as well. In his hands was Ventus's wooden Keyblade, the dark enigma snapping it in two. The two battling once more, Aqua was left extremely exhausted. Just as soon as he had appeared, Vanitas vanished in yet another dark corridor.

Eventually, Ventus found his way to the Keyblade Graveyard. Vanitas approached him, again speaking of Terra losing his identity and challenging him to a duel. Vanitas gained the upper hand mid-way, knocking Ventus down. King Mickey later appeared, healing Ventus. The two then proceeded to fight the dark enigma, Vanitas leaving yet again upon his defeat.

A later event shows Master Xehanort and Vanitas conversing in the Keyblade Graveyard, Ventus lying unconscious beneath them. Ventus awakens on Destiny Islands, Vanitas speaking to him before Ventus fled the world.

When Terra, Ventus, and Aqua approached their final battle with Vanitas and Master Xehanort at the Keyblade Graveyard, intense battles ensued. The two darklings met up with the Keyblade wielders, Terra charging them. Master Xehanort intervened, however, blocking Terra's path with massive rock formations. As Terra continued to pursue Master Xehanort, Vanitas went after Aqua and Ventus. The two fought valiantly against the dark warrior, but not before he returned to Master Xehanort's side after Ventus was frozen. He battled Terra alongside Master Xehanort, Xehanort later commanding Vanitas to go after Ventus and Aqua again. Vanitas attacked Aqua from above, Ventus's warning too late. Aqua was knocked unconscious, Vanitas preparing the final blow while Ventus lay helpless and frozen. Ventus summoned all of his willpower, however, standing and facing Vanitas. The dark enigma revealed his face, summoning many Unversed around Ventus. In a burst of light, Vanitas and Ventus were transported to the Awakening, Ventus's pillar now hosting a picture of Vanitas, as well. Vanitas wielded an incomplete version of the X-Blade, Ventus's final battle ensuing. Their pillar in the Awakening shattering as they fought, Vanitas later faded out of existence into the light along with Ventus and the X-Blade.

Meanwhile, Aqua had been rescued by King Mickey. When she awoke, she desperately called out for Ven. She then found him standing in a far corner, approaching him. When he didn't respond to her cries, she was shocked to see his eyes turn gold, as well as Vanitas's suit. Ventus then began to speak with Vanitas's voice as well as his own, summoning the X-Blade and attacking. After their final battle, Aqua destroyed the X-Blade, the resulting explosion freeing Ventus from Vanitas's possession. They took an unconscious Ventus to the Mysterious Tower, Vanitas no more.

Appearance
Vanitas wears a black and red organic-looking bodysuit and a silver helmet covered with dark glass, hiding his face from view. It is revealed his face is identical to Sora's, aside from his yellow eyes and black hair. His suit's appearance is quite similar to Riku's Dark Mode from Kingdom Hearts and Chain of Memories. He wields a Keyblade that is colored in red and black, also bearing two blue eyes that were previously unique to Riku's Soul Eater and Way to the Dawn.

Fighting Style
Vanitas is a skilled warrior with the Keyblade and with magic. He is seen casting thunder and blizzard magic, performing complicated acrobatics, and even rides the flying Keyblades that Master Xehanort sends out.

Also, Vanitas's battle stance (as seen in a trailer) greatly resembles Riku's battle stance. In actual gameplay, he is shown to fight Aqua in Radiant Garden sometime during Kingdom Hearts Birth by Sleep.

Trivia

 * Vanitas is shown reenacting a scene with Ventus mirroring Sora and Riku from the openings of Kingdom Hearts and Kingdom Hearts II, in which he holds out his hand to him. This further indicates a connection between Ventus/Sora and Vanitas/Riku.
 * Tetsuya Nomura confirmed that Vanitas's identity will be revealed at the end of the story of Kingdom Hearts Birth by Sleep.
 * After his first spoken line, Nomura made a joke saying that he was to voice Vanitas. Nomura later stated that Vanitas is voiced in Japan by an actor known to be difficult to hire.