Complex sentence: Chiyoko's story is ultimately one of faith and longing, while the device of segments from earlier movies allows the setting, characters, and perhaps most importantly the visual style of the film to change suddenly in interesting ways.
Split into simpler sentences: Chiyoko's story is ultimately one of faith and longing. While the device of segments from earlier movies allows the setting, characters, and perhaps most importantly the visual style of the film to change suddenly in interesting ways.