I think my first attempt at a fringe force tradition was the Shapers of Kro Var. I was one of the first to attempt it, even going so far as to legitimately crossover Avatar the Last Airbender to Chaos (don't look at me like that, I was young and stupid three years ago). When that didn't go over well, I went legit and made a minor faction for a while that made a few cool stories but ultimately didn't go very far.
Otherwise everything's been a unique variation of Sith, with the occasional Jedi that gets no more than 20-50 posts before being abandoned out of boredom.
Until Zambrano the Hutt. Although he started out as a psychopathic murderer who fit right in comfortably with the rest of the Sith, he is now part of something completely different: The Seekers of the Rift. It's an original order within the Primeval that adheres to a simple mission, to open the eyes of the blind. The blind of course, are all those who do not know the truth that is Sargon, the main deity of the Primeval faith. There are three sects within the Riftseekers, and he is a Riftborne. A Riftborne serves Balagoth the Dead One, the second creation of Sargon the Tongueless Speaker, and is the god of Chaos and Change, not necessarily death. The other sects are Riftwalker and Riftsinger, who serve Halrarmenth the Broken Creator and Nogras the Starmaker. Riftwalkers use subterfuge and any means to convert, while Riftsingers seek to enlighten.
This character uses blood magick that is very very similar to Dathomiri magick (except I can only use it on things that has blood within it), and given his unique outlook on the Force (he believes in his own subsect of the Primeval faith that I have named as L'ans Zodou, which is basically legit Voodoo, not the hollywood exaggeration... Z Hutt just happens to be a physcopath) he has become the farthest thing from standard.
It's fun stuff!