The Cyclops is a huge, stationary Vex construct with a powerful Void weapon. Guardians think of Cyclops as gun platforms - batteries installed to protect key points with devastating mortar fire.
But some evidence suggests that the Cyclops is in fact an enormous sensor or beacon, and that its weapons capabilities are secondary. What the Cyclops senses remains unknown, although its mind core is vast. It may play a role in the Vex networked intelligence, or in navigation across space and time.
A damaged Cyclops can be forced into a state of punch-drunk confusion, its inputs overwhelmed by hostile fire. This can result in fratricidal kills on other Vex units.