Darkra

You fill your spellcasting focus with necrotic energy and swing it out in an arcing motion, causing a wave of energy to burst out towards in a cone. All creatures in a 30ft. cone originating from you make a Dexterity saving throw against your spell save DC. On a failure, they take 3d8 necrotic damage and half as much on a success.

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