You know you should get arrow rain and shoot the stalag-whatevers at the top when the dragon is under it. It does 470 dmg each time a stalag-whatever drops.
url to your more helpful vid asking for how to make bone storm: http://recipeblog4cookscutlery.brighterplanet.org/recipes/sin-mark-final-battle-ending-plot-plus-3-spell-recipes
Apparently if the boss pushes you all the way to the way behind you, he can't hurt you. It was either that or the fact I had the life regenerating charm.
He's not too difficult so I don't see why a video is necessary.
I think it would be cool for you to list all the spells, required runes, and a description of each spell (Be nice if they were in order too) on here. Then people can look up the spells without having to watch the youtube video (spoiler) and they could get all their information at once right here.