Baalzebul's Pestilence

You summon a swarm of mites, fleas, or other parasites to consume the flesh of a target of your choice. The target must make a Constitution saving throw or take 3d8 poison damage and the bugs persist until the next round, but if it's a success, the target takes half damage and the swarm dissipates. The next round, the creature must make another Constitution saving throw at the start of its turn, or take an additional 1d8 onto the initial 3d8 poison damage. This amount increases by 1d8 poison damage with every round it persists.