You magically create a flaming crown upon your head, which radiates bright light for 30 ft and dim light for another 10 ft. while this spell is active, you gain an AC equal your spell save DC, and can use your reaction to double the ac of any creature within 30 ft of you if they are attacked. any creature that targets you with an attack, and misses takes 3d12 fire damage and has it's maximum health decreased by half that amount for the rest of the spell's duration.