Crushing Darkness

You create a 20-foot-radius Sphere of darkness centered on a point within range. For the duration, magical Darkness spreads from a point within range and fills a 20-foot-radius Sphere. Darkvision can’t see through it, and nonmagical light can’t illuminate it.

Each creature in the Sphere makes a Constitution saving throw, taking 5d8 force damage on a failed save or half as much damage on a successful one. A creature must also make this save when if it ends its turn there. A creature makes this save only once per turn. All creatures within the sphere have their movement reduced by 1/2.

Using a Higher-Level Spell Slot. The damage increases by 1d8 for each spell slot level above 5.