Ba'azi's Blizzard

A bright cerulean streak flashes from your pointing finger to a point you choose within range and then blossoms with a low wisp of wind into a frozen hellscape. Each creature in a 20-foot-radius sphere centered on that point must make a Dexterity saving throw. A target takes 6d6 cold damage on a failed save and their speed is halved until the end of your next turn, on a successful save, they take half as much damage with no reduction to speed.

The blizzard spreads around corners. Any creature that fails their Dexterity Saving throw

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.