Blood Shrapnel

You imbue your weapon or ammunition with cold hemomancy, causing blood to freeze when it splatters. On a hit, you cause frozen blood to scatter like shrapnel in a 15 foot cone behind the target if the weapon damage is piercing, or to one of the side of the target if the weapon damage is slashing. Each creature in that area must make a Dexterity saving throw, taking 4d6 necrotic damage on a failed save, or half as much damage on a successful one.

If you hit a target that does not have blood, this spell does not work.

At higher levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 for each slot above the 2nd.