Channel Power

You channel all your magic energy into one great blast. You shoot a ball of pure force and power. The target takes 30d20 force damage and is stunned for one turn. You also take 1d4+1 levels of exhaustion and you can't cast spells for the next 10 minutes. Every subsequent day you can make a DC 15 constitution saving throw to remove one level of exhaustion. Finally you can not cast this spell again for one moth.