Umbral Agony

A blast of shadowy energy is unleashed from you in a 60-foot cone. Each creature within that area must make a Constitution saving throw, doing so with disadvantage if they’re standing in darkness. On a failed save, a creature takes 6d6 necrotic damage if it is standing in bright light, 9d6 necrotic damage if it is standing in dim light and 12d6 necrotic damage if it is standing in darkness. On a successful save, a creature takes half damage.

At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, the damage increases by 1d6 for each spell slot level above 6th.