The final battle has just begun.
. Sigh, this episode ends with a cliffhanger, in the form of Round 3 between SotF Yuji and Shana.
Either way, the Bal Masque has made the first step of creating Xanadu, by erecting the massive tall structure. Any further fight between Bal Masque and Flame Hazes may probably benefits Bal Masque more, since the longer they fight, the more complete the process of Xanadu is. By then, Flame Hazes will not be able to stop the process anymore.
I do understand from other threads here that Flame Hazes have some concerns whether the Crimson Denizen can be effectively prevented from devouring humans in Xanadu, thus they want to prevent the creation of that utopian world. Then again, as others have mentioned, should they defeat Bal Masque, Flame Hazes just do not have any other alternative to offer, to solve the problem. Reverting to status quo is not going to end the war between Flame Hazes and Bal Masque.
Anyway, I just cannot wait for Episode 19!