The Covenant was founded to preserve the lightside at all costs. When the original faction of the Covenant fell, Luminotia Pendragon took the remaining Purgers who were fiercely loyal to her and took back to the Jedi but still called upon to hunt sith when needed. Only the Covenant Purgers remain, in small numbers as well. They soley fought for Luna's ideals which they saw as their own for they were taught to obey their leader no matter what. When Luna returned to the lightside the Purgers were given the same orders they were when they were still the faction: the Protect and preserve the lightside at all costs. Upon Luna's exile, Damacus Feral took up leadership.
The Purgers are profiecient users of the Shien/Djem so and Ataru forms since they will mostly fight in one-on-one and speedy situations. The Purgers use the Force to use their acrobatic skills to overwhelm and out-maneuver their target. Purgers are trained to hide in the shadows at all times and remain completely concealed to the naked eye using various force techniques such as Force Concealment, Force Cloak, and even Alter Image which they are trained extensively on. If propelled into a duel, Purgers never strike first, they wait till their opponent strikes and they use various taught techniques to subdue them in one strike. In the shadows the Purgers are trained to drag targets back and slit their throats, that's the typical kill. Purgers are also trained not to rely on sight but to rely on their senses just incase nothing is visible.