User blog comment:Xilinoc/Ch. 571 (Yachiru's gonna wreck it)/@comment-11446176-20140305130913/@comment-10205398-20140305141440

On both the Zanpakuto page and the Kenpachi Zaraki page on this wiki, his Zanpakuto is said to be in constant release. It doesn't grant him any extra abilities since he doesn't know it's name or how to communicate with it, but it's appearance is not that of a sealed Zanpakuto.