User blog comment:Xilinoc/Everything but the Rain op. 10 - "Prinz von Licht"/@comment-8295743-20130515181937

I'm quite sure Uryu hasn't really turned traitor. It's obvious he is a spy sent by Urahara and Ryuken to learn more about the Vandenreich. And I have to say, I don't have much hope for Uryu surviving the series. If the Vandenreich don't kill him, the Shinigami might, as part of a Quincy extermination to keep yet another war from beginning.

So when the Old Man failed to Yhwach a thousand years ago, it seems he was sealed away. Perhaps by Soul Society through the use of some ancient, forbidden Kido. But it may be possible the original line of Quincy sealed him away just to keep him alive. We have no idea the extant of the damages of the original Shinigami-Quincy War. Perhaps Yhwach only survived because of his own people.

Ugh, this chapter gave us way too many more questions than answers. Hopefully Kubo answers most of these in the manga itself, and then cleans up minor details/answers other questions in a final character book. And then we have to convince Viz to actually translate and release it.