Fracture

The Fractures were a race of beings who existed in the Void. The Twelfth Doctor compared them to antibodies, acting on the behalf of the Multiverse. They claimed to be trying to prevent chaos by targeting beings that crossed the Void. Their true forms were shifting forms of light; when they possessed humans to access worlds outside the void, their hosts gained the properties of the Fractures' shifting ability. Their hosts' minds were banished to the void as astral projections. (COMIC: The Fractures)