You whisper a string of infernal words, heard only by one target in range, the target must make a Wisdom saving throw. Any creature that can't be charmed succeeds on this saving throw automatically, and if you or your companions are fighting a creature, it has advantage on the save. On a failed save, the target has disadvantage on Wisdom checks until the spell ends. The target can attempt to make the save again at the end of each of its turns. The spell ends if you are incapacitated or can no longer speak.