I have an idea for an original character in an alternate prequel trilogy, inspired by aspects of Qui-Gon Jinn and Count Dooku.
The idea is that the Jedi Knights have settled into the role of being the Republic's mystical police force, concerned with mortal threats and generally not focusing on the fight against the Dark Side; but there is one Jedi (whom I have chosen to name Templar Jinn) who has peered into the contents of an ancient Holocron detailing the Force Wars of old. Templar Jinn grows wary of this threat, knowing that it will only be a matter of time before the rise of a new dark order. He strikes out from the mainstream of the Jedi Order, declaring that their complacency has made them traitors of the Light, even going so far as to personally denounce Obi-Wan Kenobi. In an incredible display of Force strength, Jinn overpowers several Jedi and escapes from the Temple. He then embarks for the farthest reaches of the Outer Rim, determined to eliminate the Dark Side before it can rise again.
He is a Light Side fundamentalist, essentially.
My thought is that Anakin's turn to the Dark Side is motivated in part by his observation of the Jedi fighting with themselves. Perhaps he is part of the mission to locate and capture/disable/kill Templar Jinn, whose actions are turning the public against the Jedi. As for what Jinn is actually doing out there, my idea is that he has set up a state with himself as the autocratic leader and policies which ensure that Force-sensitives are kept imprisoned under heavy guard and deprived of the training necessary for them to fully realize their abilities. In Jinn's warped mind that is the only way to avoid repeating the savagery of the Force Wars. Maybe there's a secret police force of clone warriors loyal only to Jinn himself.
I find it really interesting to think of how this intersects with the Clone Wars and the transformation of the Republic into the Empire. It also makes the Dark Side more interesting because it feels like something new happening rather than the Lucas PT's treatment of "There were a bunch of other evil dudes with red lightsabers and 'Darth' in their name running around before the rise of the Empire."