Billowing Darkness

You loosen the chains that bind the shadows to their places, unleashing their hatred and hunger.
A 20-foot radius sphere of swirling darkness appears, centered on a point within range and lasting for the duration.
The area is lightly obscured by the dark shapes within it, and non-magical light sources in the area are instantly extinguished. If any of this spell’s area overlaps with an area of light created by a spell of 4th level or lower, the spell that created the light is dispelled.

The ground in the area is covered with grasping limbs and agitated figures, making it difficult terrain. When a creature enters the affected area for the first time on a turn or starts its turn there, the creature must succeed on a Dexterity saving throw or take 3d6 necrotic damage.