The Usurper is a marvel of Protoss technology. It employs the use of a modified Stalker exoskeleton equipped with Xel'Naga plating and shielding, making it tough for its small size, and is equipped with many different technological appendages.
Although the Usurper's armament is quite weak, rivaling only the Protoss Probe, the Usurpers abilities make it more than worth its cost. Created inside the hulls of Integrators, Usurpers possess the ability to interact with enemy technology in many different ways, although they must bore into the target to do so. The Usurper may also use this "Imbed" ability to rip through small biological targets, killing them instantly.
The Usurper may shut down any technological target it has bored into through the use of a neuro-circuitry virus. This nano-technology can be employed against biological targets as well, because both machines and biological units operate through electical signals.
In addition to this ability, the Usurper has the power to inject a flurry of microscopic data-collection drones into the host. These nanites essentially "Usurp" enemy technology, which is how the Usurper gets its name.
If this was not all enough, the Usurper may cloak at the cost of slowly draining its central energy core of localized power.