Last session my players slaughtered a large quantity of demons using only one procedure. Each time the wich would use the slumber hex (a supernatural ability, so no SR applies. Moreover, he really buffed the DC his hexes) and the fighter would perform a coup de grace (wich either kills the creature instantly or results in an impossible-to-beat fortitude save). Am I missing something here? Is this a legit procedure? Im affraid they will ruin the demon-heavy adventure I prepared.