Cloud of Shurikans

You fill the air with flying shurikans in a cylinder 10 feet in diameter and 10 feet high, centered on a point you choose within range. A creature takes 4d6 slashing damage when it enters the spell’s area for the first time on a turn or starts its turn there. As a bonus action, you can move the center point of the cylinder up to 20 feet. 

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 2d6 for each slot level above 4th level.