echo (armored core vi)
An unmanned bipedal AC reassembled using classified means by ALLMIND, the new designation 'Echo' is without a serial code, though its made up parts produced by the Rubicon Research Institute under the serial code IA-C01X 'Ephemera'. Despite being developed half a century prior, like all Institute developed machines, it is able to keep up and exceed modern weapons in many aspects thanks to it's Coral-powered technology. The AC Echo has an alien but yet feminine appearance, it is painted entirely in black, silver and pink.
Echo is first encountered as an enemy unit around the mid chapters of the game simply under the designation 'Institute AC', painted entirely in silver with red arm units.
Though designed to be unmanned, when it's reassembled into the Echo, it was piloted by Ayre in the story route 'Alea Iacta Est' to assist the player character in the final mission.