Rather than an instant ability, I would rather have it be a ~1.5-2s cast like cures, uninteruptable if damage is blocked and NOT interrupt combos

This:
-Prevents GCD timer waste
-Allows sheltron synergy or for it to be weaved between enemy auto attacks, raising the skill ceiling.
-Acknowledges that emergency heals like this ability is tuned for can't wait for you to finish your combo and does not hit PLD where it is weakest, in the DPS

Let stoneskin interrupt combos, it is cross class and the contrast should help emphasise clemency is part of the jobs special skill set