@gloomyanimal It's one of those movies that focus more on mood and atmosphere than on narrative. It's got great shots but less exposition. I personally enjoyed it. A solid 7.5/10
Where Aizen denies what he is, Yhwach denies the notion to even look within at all. You are not meant to completely “solve” Yhwach by having him confess himself to you, more like supposed to infer him from the shape of everything he refuses to confront.
You have to treat his visual design, ability mechanics, poetry and sparse dialogue as psychology because Kubo rarely sits Yhwach down for conventional introspection. His refusal to introspect is itself the point.