Dark Nebula

A Dark streak falls from the sky and impacts the ground, erupting into a Dark Starry Nebulous Cloud. Each creature in a 20-foot-radius sphere centered on that point of Impact must make a Constitution saving throw. A target takes 6d10 Necrotic damage on a failed save, or half as much damage on a successful one.

The Nebula spreads around corners. It Instantly kills all Plant life, and rots objects in the area that aren't being worn or carried.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d10 for each slot level above 4th.