I could see Revan having an Emperor-style leader, with common effects for all allies, and specific ones for Jedi and specific ones for sith. Like:
All Old Republic, jedi, and sith allies have +20% offense, +20% tenacity, and recover 5% protection when an enemy uses a special ability. Jedi allies gain 10% stacking defense when they take damage (max 50%). Sith allies gain 10% health steal when they damage an enemy (max 50%). Old Republic allies gain 20% TM on a critical hit.
It would also be interesting if revan had a unique that could affect everyone, but toggle between light and dark side bonuses (light side allies gain +50% crit avoidance, ds allies have -20% tenacity; ds allies gain +50% potency, ls allies have -20% offense). It would also switch if Revan is considered a jedi or sith during battle. Something that is a nod to Revans powerful yet ambiguous nature.