When you cast this spell as an action you conjure a spear made of ice in a free hand and may hurl it as part of casting this spell.  Make a ranged spell attack, on a hit you deal 3d8 cold damage. At the start of each of that creatures turns they must make a Constitution Saving throw or take an additional 1d10 cold damage and have their movement speed reduced by 10ft, stacking on each subsequent failed save. Effect ends and Target takes half damage on a successful save.

After succeeding in the save a creature is immune to the additional effect for 24 hours.

As an action on each turn after this one you may summon a new spear to throw.

At Higher Levels: When casting this spell using a 3rd level spell slot or higher the damage a creature suffers on a failed save increases by 1d10 for each spell level above 2nd.