Attius' Burning Blizzard

You channel the forces of both Fire an Ice to harm and hinder your opponents. You select a point that you can see within range and a large ball of frost and flame manifests violently in a 20 foot radius centered on the selected point . Creatures within the area must make a Constitution Saving throw or take 2d6 Fire damage and 2d6 Cold Damage while having their movement halved until the start of their next turn, taking half damage on a success. Creatures who start their turn or enter the spells area for the first time on their turn, must make the Saving throw against the spells effects. On your turn you may move the Ball of Frost and Flame up to 20 feet as a bonus action. 

Casting this spell using a spell slot of 5th or higher increases the damage by 1d6 Fire damage and 1d6 Cold damage per spell level above 4th.