Frelsi

The Fresi were a Force-sensitive order that was rumoured to be just as old as -- if not older than -- the Jedi Order.

Unlike the Jedi, who studied solely the Light side of the Force and its aspects, and defended the Galactic Republic, and unlike the Sith Order who studied solely the Dark side of the Force, and strove for power, the Frelsi studied whatever aspect of The Force was needed for a situation.

And, also unlike the other orders, they had a philosophy that says "The Dark Side is as harmful as a blade, and the Light Side is as helpful as a drug. In order to live, one must learn to use both with equal proficiency, and learn to substitute either one." Which has drawn Grey Jedi to the order, as well as their acceptance where other orders would usually shun them away.