You unleash a bolt of unholy energy at an aberration, celestial, elemental, fey, or fiend within 60 feet of you. The creature must make a Charisma saving throw, taking 5d8 necrotic damage on a failed save, or half as much on a successful one. At the start of each turn for the duration, the creature must repeat the save, taking 3d8 necrotic damage on a failure. For each failed save made by the creature, you can ignore the components of one casting of a spell, as long as they are worth less than 100 gp. After 24 hours, the benefits of any failed saves vanish.