A black portal swirls around a targeted location you choose within range and lashes out with shadowy tentacles. Creatures in a 15-foot cube must make a Dexterity saving throw against your spell save DC or take 3d6 necrotic damage. On a successful saving throw, creatures take half damage.

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