Mordenkainen's Lost Notebook
4-level Necromancy
Choose a living creature you can see within range. That creature must make a Constitution saving throw. On a failure, you magically disrupt the subject’s internal organs, causing it great pain. Each round on your turn, the subject takes 3d6 psychic damage and becomes incapacitated. At the end of each of its turns, the target creature can repeat the saving throw; on a success, the effect ends.