he pretty much is god in human form he could make a barrier country wide that only allows people to go over if they are from the country, then send his demon lord servant and all his servants to guard that wall then use laser beam cannon to destroy any opposition.
i mean he can do anything.
its so slow this manga, i still love it but i want to see more, like the anime showed some future bits so i know she'll master at least some powers but by the time it gets there i'll be dead!