Cataclysmic Acid Rain

You call forth a catastrophic storm of acid rain in an 80-foot-radius, 40-foot-high cylinder centered on a point within range. When you cast this spell and at the end of each turn you spend concentrating on it, each creature within the area must make a Constitution saving throw. On a failed save, the creature takes 15d6 acid damage and has its AC reduced by 2 until the start of your next turn. On a successful save, the creature takes half as much damage and suffers no AC reduction.

The acid rain also affects structures, weakening them significantly over the course of the spell’s duration, potentially causing collapses.

This spell ignores resistance and immunity to acid damage.