Unversed

The Unversed are creatures introduced in, and mostly confined to, Kingdom Hearts Birth by Sleep. Terra is sent to put down an outbreak of these dark creatures in neighboring worlds, and Vanitas uses them against Ventus to strengthen him for Master Xehanort's plan. When one is defeated its negativity returns to Vanitas, who can recreate them however many times they are destroyed. They cease to exist after Vanitas is reintegrated into Ventus and destroyed in his subconscious, and are briefly restored when he returns in Kingdom Hearts III.