Borrowed Blood.
Prerequisite: Bloodcraft, 8th level
- You can draw blood from creatures around you to temporarily boost your magic. When you cast a spell of 1st level or higher on your turn, you can choose a target creature that you can see within 30 feet. That creature must make a Constitution saving throw against your spell save DC. If the creature isn't missing any hit points, it has advantage on the save. On a failed save, the creature takes necrotic damage equal to 5 times the level of the spell cast and you regain your expended spell slot after you cast the spell. Once you use this feature, you cannot use it again until you finish a short or long rest.