Chorosine's Breath

Upon casting, the user will roar out waves of necrotic energy in a 40-foot Cone. Each creature in that area makes a Dexterity saving throw, taking 10d6 necrotic damage on a failed save or half as much damage on a successful one. If the saving throw failed the affected creature's armor (if any) begins to corrode making them loose 1 AC until repaired.