Gatekeeper constructs were impervious to conventional weapons while activated. However, they could be deactivated by xel'naga relics. Terran Dominion ghost agent Stone discovered this weakness, and created artifact trucks loaded with xel'naga relics, allowing them to deactivate the gatekeepers and expose them to attack. With the aid of allied commanders, the Dominion was able to overcome the constructs and destroy the battle station.
Gatekeeper constructs appear on the Co-op Missions map "Cradle of Death". They are unattackable until disabled by an artifact truck. Once disabled, they will cease attacking, and be exposed to enemy fire. Gatekeeper constructs do not move from their spots, but will block the beacons that serve as the primary and bonus objectives on the map.
The primary attack of the constructs is Omnia Burst ability, which will fire multiple 5 damage bursts at enemies around it, dealing heavy damage to a large number of lighter units. It will also attack with a thermal beam attack, that deals 40 damage to heavier targets.
The health of the Gatekeeper constructs will increase as the mission goes on, though it varies depending on the mission's difficulty. As sections of the station are destroyed, the constructs double in health. Those guarding the bonus objectives remain at the same health. As trucks have a very low target priority and constructs hit heavily, it is beneficial to keep artifact trucks close to the frontline to deactivate constructs quickly.
- The "Omnia Burst" ability has three different names in the Galaxy Map Editor, "Amon Tentacle," "Omnia Burst" and "Omnia Claw."