Wrack

You wrack the body of a creature that you can see with a virulent, disease-like condition. The target must make a Constitution saving throw. On a failed save, it takes 14d6 necrotic damage, or half as much damage on a successful save. The damage can't reduce the target's hit points below 1. If the target fails the saving throw, its hit point maximum is reduced for 1 hour by an amount equal to the necrotic damage it took. Any effect that removes a disease allows a creature's hit point maximum to return to normal immediately.

Force Potency. If you cast this power using a force slot of 7th level or higher, the power deals an extra 2d6 damage for each slot level above 6th.