Mad Hex

As a bonus action, you cause a psychic disturbance around the target cursed by your hex spell or by a warlock feature of yours, such as Hex. When you do so, you deal psychic damage to the target and each creature of your choice within 5 feet of the attack, This attack does not miss or cost a spell slot.

The psychic damage equals your Charisma modifier (minimum of 0 damage).