God, I hate this Fullbringers bullshit all over again. This is so fucking sad, ending almost 8 years of my life in 4 chapters, damn it Kubo, fight for your shit. I don't even try to fool myself anymore with the sequel theory. I want to cry so bad.
Anyway, this chapter is just a big "wtf". I feel that this was a very desperate measure, like, I can see the editor calling Kubo and telling him: "Well, you have 4 chapters, xoxo" and Kubo just looking at his pages. Soulless.