Cryolate

A ray of blue energy beams from your hand to a point you choose within range and then erupts into a fury of ice. Each creature in a 20-foot-radius sphere centered on that point must make a Dexterity saving throw. A target takes 5d8 cold damage on a failed save, and its speed is reduced by 15 feet until the start of your next turn. On a successful save, the creature takes half as much damage.

The ground in the area is covered with slick ice, making it difficult terrain. A creature that begins it's turn on this ice must make a Dexterity saving throw. On a failed save, it falls prone.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 for each slot level above 3rd.