Ventus

Ventus, also known as Ven, is one of the main protagonists in Kingdom Hearts Birth by Sleep and Kingdom Hearts Birth by Sleep Final Mix. His name means "wind" in Latin, similar to how Sora's name is Japanese for "sky". He was a Keyblade wielder before Sora ever became one, and was apprenticed to both Master Xehanort and Master Eraqus. He is the youngest of the trio formed by himself, Terra, and Aqua.

Ventus's heart is severely damaged by the creation of his doppelgänger, Vanitas, and then again when the χ-blade forged from their hearts is destroyed. Both times, Sora's heart reaches out to mend Ventus's heart, and by the end of Kingdom Hearts Birth by Sleep, Ventus's heart has gone to sleep within Sora so that it can recover until it is fully healed and ready to rejoin his body, which lies comatose but safe within the Chamber of Waking. The official Japanese website refers to Ventus as the "Swift Wind Returning to Bonds".