Bone Storm

Target an area within 90ft of you and summon a swirling tornado, filled with razor-sharp bone shards. You summon a tornado, with a radius of 30ft, any creature caught in the tornado take 2d6 slashing and 2d6 piercing damage every turn they are in its area of effect. Every creature within the tornado must make a CON saving throw, with a DC of 20, or be blinded. The tornado lasts for 3 + your WIS modifier rounds. After it is cast, as a standard action, you can concentrate to move it 10ft in whatever direction you desire.

At Higher Levels.  When you cast this spell using a spell slot of 4th level or higher, you deal an additional d6 of slashing and piercing damage.