Blood Boil

One creature within range must make a Constitution saving throw. On a failure the target takes 2d10 necrotic damage, and takes an additional 1d4 necrotic damage at the start of its next turn. The creature must subtract the later damage from the next attack roll, saving throw, or ability check it makes. On a failure, the target takes the additional damage, and suffers no other effect. Undead, plants, and constructs cannot be affected by this spell.

When casting this spell out of a slot of 3rd-level or higher the initial damage increases by 1d10 for every slot above 2nd.