You send a spear of necrotic energy to a point you choose within range and then covers the area in a sickening, flesh-eating necrotic energy.
Each creature in a 20-foot-radius sphere centered on that point must make a Dexterity saving throw. On a hit, the target takes 6d8 necrotic damage.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d8 for each slot level above 3rd.