Absolute Zero

Make a melee spell attack against a creature you can reach. On a hit, the target takes 9d10 Cold Damage.

On hit: Roll a d6, on a 5, or 6 The hit creature becomes vulnerable to Cold Damage

At Higher Levels. When you cast this spell using a spell slot of 8td level or higher, the damage increases by 1d10 for each slot level above 8th.