4th level necromancy
Casting Time 1 action
Range 90 feet
Components V, S
Duration instantaneous (see below)
A black bolt of cracking energy shoots out from your finger at your target. Make a ranged spell attack against it to assail it with the raw negative energy of the Negative Energy Plane. On a hit, the target takes 8d6 necrotic damage and must succeed at a Constitution saving throw to avoid having their hit point maximum by the half that amount as well as suffering a level of Exhaustion. If their maximum hit points is reduced to 0, they fall unconscious until they have a maximum hit point of 1 or better. The loss of maximum hit points is recovered after a short rest. Constructs and Undead are immune to this spell.
At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 2d6 per spell slot above 4th. For every 2 levels above 4th used, the target that fails its save suffers an additional level of Exhaustion.