Clutch of Orcus

You raise your hand towards one creature of your choice that you can see within range and clench your fist. The target begins to suffer a magic-induced heart attack. The target must succeed on a Constitution saving throw or take 3d12 necrotic damage and be stunned for the duration. At the end of each of its turns, the target repeats the saving throw. It takes an additional 3d12 necrotic damage on a failed save. On a successful save the spell ends. 

At higher levels: Damage increased by 1d12 for each spell slot above 3rd.