How bout:
50% chance to apply expose to random enemy for 2 turns. If mace Windu hits an exposed enemy gain 50% TM. Double if the enemy is droid, sith, or separatist. When an ally deals damaged to an exposed en my gain 20% TM. Double if th ally was republic, clone or Jedi. Mace Windu gains 10% critical chance and an additional 5% for each republic, Jedi or clone ally. In addition he gains 20% critical damage and 10% critical damage for each droid, sith or separatist enemy. He gains offense equal to his critical chance and crit damage percentages. He gains 20% max health for every critical hit he scores.
Mouthful but it seems not OP.
Add to leader:
Jedi, clone and Republic allies have a 30% chance to expose an enemy when they attack them. (Unresistable) in addition they gain 20% TM whenever they attack an exposed enemy. While Windu is alive All exposes reaply when they end except by a hit.