Phantasmal Killer

You tap into the nightmares of a creature you can see within range and create an illusory manifestation of its deepest fears, visible only to that creature. The target must make a Wisdom saving throw. On a failure, the target becomes frightened. At the end of each of its turns, the target must succeed on a Wisdom saving throw or take 4d10 psychic damage. On a success, the spell ends. In Aethara, where everyone has seen real horrors, the nightmares this spell conjures are often indistinguishable from memory. That is what makes them so devastating.