The Gray Jedi as a concept is catching up steam after Ahsoka Tano was featured in The Mandalorian. There are many other Gray Jedi other than Ahsoka that walk this fine line in the middle of the Force.
The Jensaarai
The Jensaarai are also called the “Followers of the Hidden Truth”. It was a movement founded by a Jedi Knight who discovered an ancient Sith tome. Realizing that the Jedi stole their teachings from the Sith, he creates a new neutral order of warriors that use both Jedi and Sith teachings. The Jensaarai believe in becoming one with “The Shadow”. This tradition is based on the concept that one can use Dark Side techniques without succumbing to its corrupting effects. The Jensaarai warriors have the perfect balance between the light and dark side of the Force.
Asajj Ventress
Surprised to find her on the list? Not all Gray Jedi were originally from the light side. There are folks from the Dark Side who embraced the teachings of the light side as well. Asajj Ventress had lost her purpose in life after the events of Clone Wars ended with the destruction of the Nightsisters. She joined forces with her lover – Quinlan Vos to kill Count Dooku. In the end, Ventress sacrificed her life to save her lover Vos from being corrupted by the Dark Side. Ventress is one of those characters fans gradually fall in love with because of her unique character growth from a villain to a Gray Jedi.
Jal Shey
The Jal Shey were a nomadic group of Force-Sensitives that studied the Force from a purely intellectual perspective. They were against war and violence. Documented history from the novelization of The Clone War movies and Knights of the Old Republic 2 put them a little over 4000 years old. They were scholars and diplomats who wanted to unlock the secrets of the Force without resorting to war, although they knew war brings out the best in individuals. The Jal Shey were hefty armor and practice basic defense skills. They are one of the oldest Force Orders in the galaxy.
Imperial Knights
After many decades of Emperor Palpatine‘s death, a new Empire takes over the Galaxy. But this time, the Emperor is not a worshipper of the Dark Side. Instead the new Emperor carefully walks a balanced line between the two opposing sides of the Force. Bolstering his ranks are the Imperial Knights. They are Gray Jedi that exist only to serve the Emperor as long as he does not succumb to the dark side. They have forgone the monk like traditions of the Jedi Order and believe that the rule of law is the will of the Force.
Revan
The term Gray Jedi basically encompasses any Jedi that goes against the Jedi Order and the Council but still remains a force for good. Revan was a Jedi during the Mandalorian Wars, an event that happened 4000 years before Luke Skywalker destroyed the Death Star. Frustrated with the Jedi Council’s refusal to help the Old Republic, Revan rebelled against the Order, took a legion of followers with him and defeated the Mandalorians. He later turned on his own people and succumbed to the Dark Side. But before he did, Revan walked the path of the Gray Jedi.
Bendu
The entity known as Bendu or Jedi-Bendu represents neutrality and the true middle path of the Force. In Rebels, Bendu aids Ezra Bridger and his master when they come seeking true knowledge about the secrets of the Force. Bendu is an entity that is the embodiment of anti-interventionism. The Gray Jedi philosophy probably began with this ancient being seeding the Galaxy with its teachings sometime in the past. That makes for a good story element to explore in future Star wars films.