User blog comment:Xilinoc/Ch. 677 - Horn of Salvation 2/@comment-11446176-20160609110912/@comment-24769684-20160609115338

It's common sense to not pull out all the stops upon starting the battle. If the enemy overpowers you, you're through.

And from a manga standpoint, there's no way any author would do that, as it would ruin the suspense of the battle