Colossal crystals of ice plummet to the ground at four different points you can see within range. Each creature in a 40-foot-radius sphere centered on each point you choose must make a Dexterity saving throw. The sphere spreads around corners. A creature takes 18d6 cold damage and 20d6 bludgeoning damage and is slowed by 15 feet on a failed save, or half as much damage on a successful one. A creature in the area of more than one crystal is affected only once.