Level 6 Necromancy (Sorcerer, Warlock, Wizard)
Negative energy ripples out in a 60-foot-radius Sphere from a point you choose within range. Each creature in that area makes a Constitution saving throw, taking 8d8 Necrotic damage on a failed save or half as much damage on a successful one.
Using a Higher-Level Spell Slot. The damage increases by 2d8 for each spell slot level above 6.
Damage by slot level: 6: 8d8, 7: 10d8, 8: 12d8, 9: 14d8