Ball Lightning

You create a 5 foot wide ball of crackling enegry that travels in a straight line 30 feet per round for 8 rounds. All creatures that are touched by this spell make a DC 17 saving throw, they take 10d10 lightning damage on a failed save or half on a successful one. The ball moves through all non magical barriers. You may attempt a DC 19 INT check to change the direction of the spell. This spell can be dispelled.