Blood Boil

As you cast this spell you take 12 damage. Make a spell-attack role on a hit the target takes 5d6 points of necrotic damage and must make a constitution saving through. On a success the target takes 3d6 necrotic damage and the spell ends. If the target fails they take 1d4 constitution drain and, for the spells duration, at the start of each of their turns must repeat the save. As soon as the target succeeds the save once the spell ends immediately.