Void Bunnies

Tapping into the power of the void you can create a shadowy 40ft circle on a point you can see. Void bunnies will begin to dive from the circle attacking all creatures within the radius. All creatures within this circle must succeed on a DC 22 DEX saving throw or take 12d6 magical bludgeoning or half as much on a successful throw. The void circle counts as rough terrain, if a creature starts its turn in the void circle, it must make another saving throw or take damage again.  

Using a Higher-Level Spell Slot. The damage increases by 3d6 and 5ft radius for each spell slot level above 4.