Circle of Undead

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 76 (8d8+40) necrotic damage on a failed save, or half as much damage on a successful one. If a creature within the spell drops to 0 hit points will become an undead thrall of a challenge rating equal to half your spell modifier that obeys your command. If a creature ends its turn on the affected area they must make a Constitution saving throw, taking 22 (5d8) necrotic 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 9th level or higher, the damage increases by 4d8 for each slot level above 8th.