Volume 18 is out over at Amazon and elsewhere. It's an Aika volume and the spreads are magnificent for this volume. Here are the chapter titles:
Chapter 2 and 3 are bit vague in english but the former is "Takes Over" as in succeeding something and "Order" in the latter is order as in a directive. Both were weirdly straightforward in japanese but all the decent possible translations I had in my head turned out misleading in one way or another. Chapter 7's Peak could also just as easily be about a mountain peak or the abstract concept of peaking at something but that was also just as ambiguous in the original. Considering the guildies this time are all named after greek gods I wouldn't be surprised if Olympus features into that chapter. I'm quite hoping that the battle royale shown in the spread will be as intense in the writing as it seems in the art. Also, Mizusawa strikes again with his eeriely on point tokusatsu coincidences. This volume had to have been finalized and gone into print before Zero One even started but here I am getting spooked in the first chapter. I really have to wonder if this doesn't actually have an in with someone at Toei or something.