Afflict Line

You invoke the darkest curses upon your victim and his or her descendants. This spell does not require that you have a clear path to your target, only that your target is within range. The target must make a successful Wisdom saving throw or be cursed until the magic is dispelled. While cursed, the victim has disadvantage on ability checks and saving throws made with the ability score that you used when you cast the spell. In addition, the target’s firstborn offspring is also targeted by the curse. That individual is allowed a saving throw of its own if it is currently alive, or it makes one upon its birth if it is not yet born when the spell is cast. If the target’s firstborn has already died, the curse passes to the target’s next oldest offspring.

Ritual Focus. If you expend your ritual focus, the curse becomes hereditary, passing from firstborn to firstborn for the entire length of the family’s lineage until one of them successfully saves against the curse and throws off your dark magic.