Whirlwind of Souls

Reaching into the land of the dead, you call forth a torrent of wailings souls to surround your enemies. The bones of long burried corpses spring from the earth--battering everyone in a 15 foot radius for 6d6 bludgeoning. Additionally, the wailing screams of these disembodied souls cause 6d6 psychic damage. When a target starts its turn in the whirlwind, it must pass a wisdom save or take more psychic damage. The first round of damage is 6d6, then each round is reduced by 1d6 until the spell fades or the caster loses concentration. As a bonus action, the caster can move the whirlwind up to 15 feet.