Prerequisite: The ability to cast at least one spell
You have developed the ability to exert your body in order to go further with your magic. You can use your reaction to spend any number of hit dice and make a DC 10 Constitution check. This DC is increased by 1 per hit dice spent. On a success, you regain one spent spell slot of a level equal to the amount of hit dice spent. On a failure, you suffer psychic damage equal to the number of hit dice spent. This damage cannot be reduced. You can only regain spell slots of 5th level or lower using this feat.