Vamster Cyclone

You conjure a living cyclone of undead vampiric hamsters. A 20-foot diameter cyclone  of hungry vamsters appears, centered on a point with range and lasting for the duration. The sound of gnashing teeth and squeaking can be heard up to 30 feet away.  On your turn as a bonus action you can direct the cyclone up to 30 feet.

 Any creature that starts its turn in the area takes 2d6 piercing damage. Any creature that ends its turn in the area must succeed on a Strength saving throw or take 2d6 necrotic damage as the Vamsters drain your life energy. In addition, for every  2 consecutive turns a creature stays within the area affected by the cyclone,  that creature gains a level of exhaustion as blood loss  mounts.