Death Knell

Lacing your touch with shimmering necromantic power, you lash out at a creature within 5 feet of you with a melee spell attack.

The cavernous knell of death tolls through the creature's body, dealing 4d6 necrotic damage. Additionally, the creature must make a Constitution saving throw if it is missing hit points; on a failed save, the creature becomes vulnerable to necrotic damage dealt by this casting of the spell.

If this spell reduces a creature to 0 hit points, it dies as you absorb its vitality for yourself. When this happens, you gain temporary hit points equal to the amount rolled for the initial damage of the spell, and a +1 bonus to your melee attack rolls while you retain the temporary hit points.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 per slot level above 2nd.