[@The 42nd Gecko]

As[@TheWindel] said, I dislike the is of her turning to light because (take RL science away for a moment), she's turning her whole body into magical energy, which is a very long step away from her usual powers. If she had a light based tome that would be completely fine, even as a last ditch trick but Meihou's powers are too broad and too powerful ad they are. As a note, I greatly dislike the nerve gas trick for the same reasons I stated above. Meihou's powers go completely against the logic of tomes already, by being that broad, vague and undefined, but they always had a theme unifying things so out was ok until now. Don't stretch it more than what is plausible.

As for the underground, no, the barrier is only above the surface. Just know that, you'll fall straight on the other scene. Whatever you do, the point is getting everyone together.

Finally, Meihou doesn't knows how Farris' tome works, you should stop having her react to stuff using meta knowledge. We will react to whatever you do, in an appropriate way.