Blood Spikes

You punish those foolish enough to attack you. When you take damage from an attack within 10 feet, you take an additional 1d4 necrotic damage (this damage cannot be reduced in any way) to draw out more blood. This blood is shaped by your magic into spikes that thrust into the source of the damage you received. The spikes deal 10d4 magical piercing damage on a failed Dexterity save, or half as much on a successful save. If you have some of the target's blood within touching distance when casting this spell the target makes the save with disadvantage.

At higher levels: When you cast this spell with a spell slot of 3rd level or higher, the self damage increases by 1d4 but the spike damage is increased by 5d4.