A storm of acidic rain falls in a 20-foot-radius, 40-foot-high cylinder centered on a point within range. when a creature enters the area for the first time on a turn or starts its turn there, it must succeed on a Dexterity saving throw or be covered in the acid for the spell's duration or until a creature uses its action to scrape or wash the acid off itself or another creature. A creature covered in the acid takes 8d4 acid damage at start of each of its turns. Any nonmagical objects made of metal that remain in the cylinder for the duration of the spell are destroyed.