User blog comment:Xilinoc/Ch. 577 - SWORD/@comment-11130627-20140416155018/@comment-957629-20140417100151

Given their names are both taken from the Districts they are separately from, this point would have been obvious; Yachiru lived in Kusajishi and Kenpachi lived in Zaraki before either of them met!!

That theory is overly convoluted and stinks of bad fan fiction!! We know that a Zanpakuto spirit does not materialize unless through extensive training or using the Tenshintai that Urahara invented but only then does it allow for a three-day limit!! We know that Zaraki has had no contact until this arc with his Zanpakuto so materializing his Zanpakuto spirit is a silly theory that ignores this fact!!

Just because this happened with an Arrancar, that's right, not a Shinigami, an Arrancar does not mean it can happen to a Shinigami!! Arrancar are Menos or Hollows that have removed their mask and managed to seal and suppress their powers into the form of a weapon!! A Zanpakuto spirit is already inside a Shinigami and through use of an Asauchi and growth and interaction with the Spirits, Shinigami are able to manifest those powers and abilities!! That does not and will never stop the spirit from existing within the Shinigami and their blade!! The special case of Starrk and Lilynette is that one being was too powerful to exist as part of a group and they split so that they would not be lonely anymore!! The powers were already there, they just split, not the same thing, no training involved!!

Man that theory, which I only heard of today, is as bad as some of those FanFics that have Yachiru randomly turn into a "big breasted pink haired beauty" for no reason other than to copy the special case of Nelliel!! Let's stop with randomness and focus on facts that were already established before we learnt that Yachiru was her own independent Shinigami with her own Spirit!!