Control Shadow

You weave an intricate illusion around a target creature that is casting a shadow. The target makes a Wisdom saving throw. On a failed save, the target believes their shadow is animate, hostile, and attacking them. For the duration, the creature treats the shadow as a dangerous creature. If the target moves, the shadow moves with it. 

While the effect persists, the target takes 6d10 psychic damage at the start of each of its turns as the shadow attacks it. The target can repeat their saving throw against this spell at the end of their turn. If the saving throw succeeds, the spell ends.