Curse of Agony

You curse one target that you can see to feel excruciating pain. Make a spell attack roll against a creature that you can see, if successful, the target will take 1d6 necrotic damage at the start of it's next three turns.

At Higher Levels: When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 2d6 for each slot level above 1st.