Vanitas

Vanitas is a being created from the dark side of Ventus' heart, one of the main antagonists of Kingdom Hearts Birth by Sleep and a Keyblade Wielder. Vanitas is cruel, ruthless and cold, having never showed any remorse or affection towards anyone. It is revealed in KIngdom Hearts Birth by Sleep that Vanitas is the source of the Unversed, the creatures fought by Terra, Ventus and Aqua. After his creation, he succeeded Ventus as Master Xehanort's apprentice and assisted his Master in attempting to forge the X-Blade. While he started out as a faceless being, Ventus' connection to Sora caused Vanitas to develop a striking resemblance to the boy. Vanitas will appear in Kingdom Hearts III as a member of the "true" organization. Although his official introduction occurred in Kingdom Hearts Birth by Sleep, Vanitas was first seen in the secret ending of Kingdom Hearts II.