Death Knell

An overwhelming echo of the realm of death explodes from a point you choose within range and then blossoms with a low roar into an explosion of necromantic energy. Each creature in a 20-foot-radius sphere centered on that point must make a Charisma saving throw. A target takes 8d6 necrotic damage on a failed save, or half as much damage on a successful one.

The dark wave spreads around corners.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.