Crystal Shards

You summon a swarm of crystalline shards that fly wildly on a 5 feet cube within range. Any creature in the area when you cast the spell must succeed on a Dexterity saving throw or take 1d6 points of slashing damage. A creature must also make the saving throw when it enters the area for the first time on a turn, or ends its turn there.

The spell's damage increases by 1d6 when you reach 5th level (2d6), 11th level (3d6), and 17th level (4d6).