Emak's freezing flame

You produce and hurl a small ball of flame with a icy blue center at a point you choose within range which then blossoms with a low roar into an explosion of flame, which is followed almost instantaneously by a chilling wave of freezing energy. Each creature in a 20-foot-radius sphere centered on that point must make a Dexterity, strength, and then constitution saving throw, with the DC being your spell save DC. the DC for all three saves decreases by one for every 5 feet a target was from the central point of the explosion. A target takes 6d6 fire damage on a failed dexterity save, or half as much damage on a successful one. A target is pushed 10 feet away and knocked prone on a failed strength save, and pushed 5 feet and not knocked prone on a successful one. on a failed constitution saving throw, a target takes 2d6 cold damage as ice begins to cover them, restraining them until they succeed on a strength check to break the ice. if the DM likes puns, it can be a charisma check instead. on a successful saving throw, the target takes half damage and gains advantage on the check to break the ice.

The Explosion spreads around corners.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, both damages increase by 1d6 for each slot level above 3rd.