Dedricks haunting shroud

A dark cloud forms around a willing creature you touch and dark cloud-like wraiths spiral around them in a 20 foot radius. For the spells duration or until the caster loses concentration you have +2 ac. Any hostile creature that enters or starts their turn in the radius must succeed a wisdom saving throw or take 2d8 psychic damage (half as much on a failed save) and have disadvantage on attack throws until the end of their turn.