If you thought that Aizen was a god with his bullshit abilities, then Yhwach is going to blow your mind. This chapter gives a bit of backstory about the father of quincies and the origin and nature of his powers, presumably narrated by Haschwald. Yhwach was born as a completely physically disabled infant – blind, deaf, mute, and immobile. He did however, have to power to grant portions of his soul to other people, which also granted them all sorts of healing boosts and other abilities. At the same time though, I wonder why he was unable to heal himself. Interestingly, Yhwach’s name seems to reference Jehovah (also transcribed as Yahweh) and he was basically treated as some sort of holy relic, but once the people infused with parts of his souls passed away, power, knowledge, and skill returned to him and he regained his functions. Now he uses people infused with portions of his souls as pawns to keep himself running. Every death (regardless of quincy or shinigami) returns more power to him and makes him ever stronger. The whole war is basically just snack time for him in the grand scheme of things, if his motives are what Haschwald said.
However, his power overall is very convoluted with a lot of holes that may or may not be explained in the future. He’s been dormant for the past millennia (presumably because of a lack of souls return to him), but the quincies have still been around reproducing and dying natural deaths all that time. Also, the mass extermination was only 200 years ago, which would have boosted his strength significantly and easily restore his functions. I can only assume that since being a quincy seems to be genetic, the descendants of the people he infused also gain part of his soul. It’s not clear why the Sternritter serve Yhwach so fervently either as despite his cruelty and power it doesn’t seem they are fighting against their will. It’s possible that they were all tricked into ingesting the Sternritter initials, but I would guess that they are aware of the nature of their existence and purpose. Finally, we have Ishida, whose motives are only hinted at, but if he’s Yhwach’s “successor” then why does he also need to die and become tribute? And why would Yhwach need a successor in the first place? The implications of his power are interesting, but it also raises a lot of questions that I hope will be explained later rather than leaving us to make up theories about what’s going on.
For the protagonists, the obvious solution would be to prevent Voldemort from splitting his souls into anybody else and waiting it out until all the horcruxes die and the cycle breaks. Since Kubo probably isn’t going to drag this series out for several hundred years though, Ichigo and co. will have to find another way to defeat him. Or possibly, Aizen will come back and work some more of his plot magic.