Agonize

You contort creature's magical aura into a crucible of pain. The target must make a Charisma saving throw or, for up to one minute, whenever the target takes damage, it takes an additional 1d4 psychic damage.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d4 for each slot level above 3rd.