[Zabimaru]

Maybe Zaraki would not be much of a help because I believe they have to find another way than just crushing the humanized zanpaktou since it's possible that they vanish...
They said Muramasa had the ability to awake the primary instinct of each Zanpaktou ... maybe it's kind of brainwashing so in the end ... they find a way to regain the Zan's consciousness or sth like this...