Vile Necrosis

You point your finger towards a creature within range, projecting a pale green beam of debilitating energy at them. Make a ranged spell attack against the target. On a hit, the target takes 12d6 necrotic damage, and it becomes weakened. While weakened by this spell, a target deals half damage with weapon attacks and spells. A weakened target can make a Constitution saving throw at the end of each of its turns. On a successful save, the weakness ends.