Comet´s Icy Comet

You open a tiny portal into the elemental plane of ice, from which a tiny icy comet flies out. It collides with the first target in a 50ft line from you. It has to make a Dexterity saving throw against your spell save DC. On a fail it take 4d4 piercing damage and everything in a 10ft cone behind it takes 2d4 cold damage. All creature affected have their movement reduced by 10. On a successful save the creature takes 1d4 cold dmg and the comet continues on its path, having its piercing damage reduced by 1d4.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the piercing damage increases by 2d4 and the cold damage increases by 1d4 for each slot level above 2nd