A spectral wound carves itself into your wrist, drawing forth a thin stream of blood. The pain is sharp, but the power that rushes through you is intoxicating. You take 1d4 + your Intelligence modifier damage—this damage cannot be prevented, reduced, or absorbed in any way, not even by temporary hit points.
Once this blood price is paid, you may choose a living creature within range. That creature must succeed on a Wisdom saving throw or suffer 2d6 + your Intelligence modifier necrotic damage. On a success, it takes half as much. You regain hit points equal to half the damage dealt, rounded down.
As long as you maintain concentration, you can choose a new target each turn without recasting the spell. Undead creatures are immune to this spell.