Acid Rain

Pick a spot on the ground that you can see. All creatures within 20 feet of this spot must make a Dexterity saving throw. On a failed save the creature takes 10d6 acid damage and is blinded for the duration. On a success, the creature takes half as much damage and is not blinded. A creature can make a Constitution saving throw at the end of each of its turns; on a success, it ends the blinded condition on itself.