Blood Loss

Choose a creature that is not at full HP. You cause their wounds to begin bleeding heavily and creature takes 2d8 Necrotic damage when you cast the spell. Until the spell ends you can use a bonus action on each of your subsequent turns to cause the damage again. This spell has no effect on undead, constructs or creatures without blood.

The spell ends if the creature receives healing or spends its action to stanch the flow of blood.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d8 for each slot level above 2nd.