Boon of the Blood Hex

Boon of the Blood Hex-

You gain the Hex spell if you don’t already have it.
When you cast the Hex spell you can bolster it by giving up energy to your patron for more power, You can pick one of two effects, the creature that is hexed has disadvantage on saves you cause and no one else’s unless by normal means, or You gain advantage on your first to hit the target you hex. As a result of this you take 1 level of exhaustion after the spell is dropped, then you need to make a Constitution saving throw against your warlock spell save or gain an additional level of exhaustion.

You can use this ability once per short rest