Few, if any other Bleach characters have an insta-kill ability like that, even if Yoruichi managed to defeat Soi Fon in the end. If necessary, Soi Fon can even use a cannon-like Bankai to deal ...

The physical and mental toll on Kubo made it clear that something had to change, and the decision to end Bleach became inevitable, but the biggest reason for that came from an unexpected source.