Blight of Desolation

A dark streak flashes from your pointing finger to a point you choose within range and then blossoms with a low roar into an explosion of green necrotic flame. Each creature in a 20-foot-radius sphere centered on that point must make a constitution saving throw. A target takes 8d6 necrotic damage on a failed save, or half as much damage on a successful one.

The necrotic fire spreads around corners. Green flames linger across the area momentarily, lighting any object struck for 6 seconds

Flammable objects in the area that aren’t being worn or carried start burning.

Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot level above 3.