So, I gotta say, I love the Fray die, the idea of heroes lashing out almost casually and smiting foes no matter what their actual action might be. That said, here is an idea about another possible use of the Fray die:
Impenetrable Defense: Commit Effort. While it remains committed you may roll your Fray die once per round to deflect an equal amount of damage you would receive from a successful attack against you. You may not use your Fray die to deal damage in the same round you use it for defense.
