Drain Vitality

4th-level necromancy (hemomancy)
Casting Time: 1 action
Range: 60 feet
Components: V, S
Duration: Concentration, up to 1 minute

You extract the life force of a creature with blood that you can see withing range. When you cast the spell and at the start of each of the target's subsequent turns, the target must make a Constitution saving throw. On a successful save, the target takes 4d6 necrotic damage, and the spell ends. On a failed save, the target takes 4d6 necrotic damage and suffers one level of exhaustion. Any levels of exhaustion caused by this spell go away when the spell ends.
Amplify 4. Whenever the spell deals damage to a target, you regain hit points equal to half the amount of necrotic damage the target takes.
At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d6 for each slot level above 4th .