Harm

You unleash a virulent energy on a creature you can see within the spell’s range. The target must make a Constitution saving throw. It takes 14d6 Necrotic damage on a failure, or half as much damage on a success. The damage can’t reduce the target’s hit points below 1.

If the target fails the saving throw, its maximum hit points are reduced for 1 hour by an amount equal to the Necrotic damage it has suffered. Any effect that removes a disease allows the creature’s maximum hit points to return to normal before that time expires.