Phantasmal Killer A5E

You create an illusion that invokes the target's deepest fears. Only the target can see this illusion.

When the spell is cast and at the end of each of its turns, the target makes a Wisdom saving throw or takes 4d10 psychic damage and becomes frightened.

The spell ends early when the target succeeds on its saving throw. A target that succeeds on its initial saving throw takes half damage.

The damage increases by 1d10 for each slot level above the 4th.