Castandar's Concussive Cluster

Using telekinesis, you launch a sphere of hyper-compressed ball bearings at a point you choose within range. Upon reaching the point the ball bearings explode outward at blazing speeds. Each creature in a 20-foot-radius sphere centered on that point must make a Dexterity saving throw. A target takes 8d6 force/magical bludgeoning damage on a failed save, or half as much damage on a successful one.

The ball bearings ricochet around corners.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.