One creature that you can see within range must succeed on a Constitution saving throw. On a failure, it subtracts 1d6 from ability checks, saving throws, or attack rolls for the duration. Additonally, it takes 2d8 necrotic damage at the start of each of its turns. At the end of each of its turns, the target repeats the save, ending the spell on itself on a success.

Using a Higher-Level Spell Slot. You can target one additional creature for each spell slot level above 4.