Steropes is a giant cyclopean robot deployed during the final attack on Mirage Mountain, the capital city of the Enkies. It is first seen in the background using a laser cannon located in its head to destroy a swathe of buildings. Upon noticing GARAI Steropes blocks its path and attacks. The robot primarily attacks using laser cannons, but also has a spherical unit, situated in its chest, which reflects enemy lasers and bullets. A large pair of what appear to be organ pipes are mounted on Steropes' back, but their function is unknown.
Two hundred circles later, Steropes' head armor (or a replica of it) appears over the entrance to a building in Tira.
Steropes (Στερόπης, from στεροπή, "lightning") is one of three Cyclopes mentioned by the ancient Greek poet Hesiod in the Theogony. Steropes and his two brothers, Arges (Ἄργης, "bright") and Brontes (Βρόντης, "thunderer"), were the sons of Gaia and Uranus, whose other children included the Hecatoncheires and the Titans. All three were locked away in Tartarus by Uranus, who feared their power, but were later freed by Uranus' grandson Zeus in exchange for helping him to overthrow his father Cronus. The trio fashioned the iconic weapons and armor of the Olympian deities, including Zeus' lightning bolts, Poseidon's trident, Hades' helmet and the bows and arrows of Apollo and Artemis.