Fog of Nightmares

A Cylinder of thick, clinging, silver fog that is 15 feet tall with a 50-foot radius appears, centered on a point you can see within range.   The fog spreads around corners. It lasts for the duration or until strong wind (20 miles per hour or more) disperses the fog, ending the spell. Its area is Heavily Obscured and acts as Difficult Terrain.   You tap into the nightmares of all creatures within the area and create manifestation of its deepest fears. These manifestations, which are similar to the images created by the Phantasmal Killer spell, form out of the fog and are visible only to the affected creatures.   Each creature in the area must make a Wisdom Saving Throw. On a failed save, the target becomes Frightened for the duration. At the start of each of the target’s turns, a Frightened target must succeed on a Wisdom Saving Throw or take 4d6 Psychic damage. On a successful saving throw, the creature is unaffected for that round.   Because of the all-encompassing nature of the fog of nightmares, it is difficult to escape: on any round in which it is affected, a Frightened creature is surrounded on all sides by the objects of its nightmares and cannot find a safe way to move, reducing its speed to 0.