Brave tomes, I know Tactics Universe had a hero flare. Which I greatly enjoyed.
Pikes, maybe. 2 range only? or halved accuracy at 1-range maybe. Cannot be countered at 2 range.
Wyvern mages. From a tactical standpoint, for an army, those would be brilliant. I know that they would be a little too good from a game-play perspective.
Beyond that....not sure.