User blog comment:Xilinoc/Ch. 577 - SWORD/@comment-11130627-20140416155018/@comment-6916556-20140418012728

I agree with Sun. Also, Yachiru has a Zanpakuto which is different to Kenpachi's. A Zan spirit can't have its own Zanpakuto, and materialised Zan spirits may only use their 'own' releases, a la both Zangetsus in Ichigo's inner realm.