I once suggested making Repose also apply a 5-10% damage down effect to enemies for 10s. The bosses would be immune to the sleep, but not to the damage down portion, making it an 'in case of emergency because the melee misclicked Feint earlier' tool, and an extra way for WHM to mitigate (because they don't exactly have much mit going for them atm). It would be balanced because you wouldn't be keeping this up at all times, it'd cost so much damage to do so. But it'd see use in week 1 clears where everything hits like a truck