Blades of Blood

You coat your fingers in demonic blood, imbuing the liquid with magic. You then swipe your hand as the blood flies from your fingertips and hardens forming blades which slice through nearly everything in a 30ft cone in front of you before disintegrating. Each creature in the cone must make a Dexterity saving throw. A creature takes 5d12 slashing damage on a failed save, or half as much damage on a successful one. Each creature hit by the attack can't regain hit points until the start of your next turn.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d12 for each slot level above 4th.