Lore
The Exo was first developed at the time of the Golden Age by the humans. It was initially created as tools of warfare to battle The Darkness. The Exo's thoughts were erased and their protocol was reprogrammed after the Collapse to unite all sentient entities. This act freed them from military and other duties imposed by the humans. The Exos are so complex that only the Ghosts are able to comprehend their capabilities, procedures and encoding. Inside the City, the Exo have the same status as the humans and the Awokens. They are widely regarded as siblings in arms. Numerous Exos have decided to battle against the Darkness, and therefore have obtained the gift of the Traveler and became Guardians. This act reveals that the power given by the Traveler is not merely carbon-based.
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