Something like, "You're Awesome (save continues)"? Awesome characters get a +2 to defenses and attack rolls.
The problem with this lies in level comparison. Say the warlord (or similar leader classes) can inspire heroism. What happens when the level 30 dragon uses its fear aura? Can a heroic-tier heroism effect cancel an epic-tier fear effect? Or do the effects simply stack, like bonuses and penalties normally do? That would work, if the effects in question impart bonuses/penalties.