Rupture (Cho'Gath Q)

You cause the ground to rupture in a 20-foot radius within range, erupting with jagged spikes. Each creature in the area must make a Dexterity saving throw. On a failed save, a creature takes 4d6 piercing damage and is knocked prone. On a successful save, the creature takes half as much damage and isn’t knocked prone.

Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot level above 3.