The Forbidden are a race of humans that have full control over the darkness and Heartless. Through most of the Forbiddens have been created through experiments. The only known member of this race is currently Judea.
Forbiddens have the ability to control and spawn Pureblood Heartlesses from their bodies by creating black orbs of darkness that the Heartless will emerge from.
Forbiddens have the ability to manipulate darkness to form Corridors of Darkness so that they can travel to different worlds.