User blog comment:Xilinoc/Ch. -547 - The State of Affairs op. 1 - "Expectations"/@comment-11163184-20130724184619/@comment-11051098-20130727175055

Seeing as Quincies disrupt the balance of the souls by permanently destroying Hollows, I'd say Karin and Yuzu would be better off as Shinigami. And their father is a former Shinigami captain, who would be better to train them than him?

It might be that Ichigo in the end will defeat Yhwach with not too much effort, and that Uryû, if he really is on the enemy's side, will become the strongest enemy to be defeated.