Black Ice Blast

A black streak flashes from your pointing finger to a point you choose within range and then blossoms with a low roar into a shattering ball of black ice. Each creature in a 20-foot-radius sphere centered on that point must make a Dexterity saving throw. A target takes 8d6 cold damage on a failed save, or half as much damage on a successful one. The user of the spell suffers 1d4 damage from Black Ice exhaustion.

The Ice shatters around corners. 

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.