Prerequisite: requires a wisdom score of 13 or higher
you can cast already expended spell slots at the expense of your hit points and cause temporary debuffs to your attributes.
damage taken depends on the slot level: (5 x slot level)
concentration spells give you disadvantage on all rolls until you complete a long rest.
instantaneous spells give you disadvantage on strength, dexterity, and constitution rolls until a short or long rest.
If a spell requires a casting time, you take 1 additional damage for every 10 seconds of casting. this is added to the slot level damage.
healing spells don't work if your healing pool is empty.