Death Lightning

Drawing on the powers of the corrupting prince, you call down twisted lightning in a 10ft radius, 60ft high cylinder around you. All creatures besides you within that area must succeed on a Dexterity saving throw, or take 10d10 lightning damage. The space then become tainted by Death Rot and all creatures that enter that space until the start of your next turn must succeed on a Constititution saving throw, or take 5d10 necrotic damage.

At Higher Levels. When you cast this spell using a spell slot of 7th level or higher, the lightning damage increases by 1d10 for each slot level above 6th.