The purge trooper was a precursor to the dark trooper, created when the Empire wanted an anti Jedi battle droid. Some of its design characteristics where incorporated in the Dark Trooper phase III.
Characteristics:[]
Primarily designed to combat force users the ten foot tall Purge trooper's main weapon is an energy blade extending from its right wrist (resembling a small lightsaber), it is also armed with an arm mounted force field and a shoulder mounted seeker missle launcher. Due to their size and strength if they get close enough they will attempt to pick up an opponent and hurl them to the ground.
They are also constructed with magnetic plates on their feet making push/grip useless against them, and, being designed to combat Jedi have a Duranium can easily stand up to one in close combat, their only real weakness is force lightning being, of course, androids.