Tension

Battle is Stressful!
Or that's what those poor adventurers you hire say. So it's a well-known fact on the battlefield that psyching up gives you more focus. Or something like that.

Psyching Up takes an Action, by default, and there are Four Tiers of Tension. Tense, Very Tense, Super Tense, and SUPER HIGH TENSION. For your next action (or bonus action) taken, you deal more damage, heal more, or have greater effect on your spells.

Weapon attacks and spells with attack rolls add an additional set of weapon/spell damage die for each level of tension on your attacks for that action. So a greatsword attack adds another 2d6 damage.

Healing effects receive an additional die to add to the amount healed per level of tension.

Area-of-effect damage spells receive a free spell level per level of tension.

Non-damaging effects inflict a -1 penalty on the saving throw per level of tension, and inflict disadvantage at a level of SUPER HIGH TENSION.