Miyuki is Tatsuya's only real weakness. Too bad she is absurdly powerful herself.

They didn't show Miyuki's most powerful spell... She isn't even an elementalist...

All in all, I enjoyed this show. Some parts were poorly done (like WTF were those soldiers standing around for? Take cover, dammit), but at least they kept the parts I liked, mainly OP Tatsuya, brocon Miyuki, and the short but sweet battles.