From Halopedia, the Halo wiki
The Reactive Cyclops is a Blitz card available for use by players playing as the UNSC in Halo Wars 2, particularly in the Blitz and Blitz Firefight modes. The Reactive Cyclops has the following attributes;
The Reactive Cyclops is classed as an anti-vehicle mech, this unit does well against any vehicle units but it's ineffective against air & infantry.
Due to the reactive shield it has, the Cyclops can be slightly more effective against all units including aircraft and infantry, especially anti-infantry units.
List of appearances