CIRCLE OF DEATH - Necromancy - 6th Level

Casting Time: 1 Action
Range: 150 Feet
Components: V, S, M (the powder of a crushed black pearl worth at least 500 gp)
​Duration: Instantaneous

  A sphere of negative energy ripples out in a 60-foot-radius sphere from a point within range.  Each creature in that area 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.

At Higher Levels.  When you cast this spell using a spell slot of 7th level or higher, the damage increases by 2d6 for each slot level above 6th.

Source: 5th Edition SRD, Player's Handbook
Class List: Sorcerer, Warlock, Wizard.