GAIA

GAIA is a hyper-powerful artificial intelligence that played a major role leading up to the events in Horizon Zero Dawn. The single most powerful, most advanced A.I. ever created, GAIA was Project Zero Dawn’s governing A.I. With its suite of nine subordinate functions, GAIA oversaw Zero Dawn’s successful restoration of life to Earth after its eradication by the Faro Plague.

However, hundreds of years after doing so, a mysterious signal turned GAIA's subordinate functions into A.I.s themselves. One of them, the erstwhile extinction failsafe protocol HADES, attempted to seize control of Zero Dawn to again end all life. GAIA resorted to self-destructing to fend it off. In hopes of stopping HADES, as well as being eventually rebuilt and rebooted, GAIA created a clone of its creator, Dr. Elisabet Sobeck, who would have access privileges to use the system’s master override to purge HADES, defeating it. That clone is the Nora huntress Aloy.