Board Thread:General Discussion/@comment-27148615-20151113005149/@comment-6697950-20151113124619

The Alicization arc consists of two major sub-arcs: the Human Empire sub-arc and the Dark Territory sub-arc. Volumes 9-14 compose the former, while volumes 15+ compose the latter. Asuna only logs in during the latter.

Unless major content cuts are made (which will most likely be made seeing as anime isn't really suitable for in-depth explanations and they take up a considerable portion of volumes 9 and 10), the first sub-arc alone should need a two-cour season of its own.