A 20-foot-radius zone of oppressive darkness forms around you, twisting the area into an unnatural void. The darkness moves with you, and creatures of your choice within the area must make a Constitution saving throw at the start of their turn. On a failed save, they take 3d8 necrotic damage and lose 10 feet of movement for the turn. On a successful save, they take half damage. Creatures frightened within this zone have disadvantage on saving throws against this spell. The zone is heavily obscured for all creatures except you. At Higher Levels: When cast using a 4th-level spell slot or higher, the necrotic damage increases by 1d8 for each slot level above 3rd.