Board Thread:General Discussion/@comment-10786787-20130613005503/@comment-5693502-20140609070725

Stefan (Shikai - "Rust & Shatter") wrote: No matter what ability is used, the rule of greater Reiatsu still applies, even to Kenpachi's Zanpakuto. Remember how Aizen repelled Suzumebachi's Nigeki Kessatsu, using nothing but his own Reiatsu? That means that anyone with greater Reiatsu than Kenpachi should be able to stop an attack from Nozarashi. Of course, there can't be more than a handfull beings that could pull that off; like Ichigo, Aizen, the Soul King, and maybe the Royal Guard. It's reasoning like this, why I think that Nozarashi is simply a pure melee-type with no special ability. In the case of Aizen, his reiatsu was so overwhelming in comparison to Suì-Fēng's that her ability didn't work, whilst when Yoruichi (who has a similar, if not greater, level of reiatsu than Suì-Fēng) faced Nigeki Kessatsu, the ability would have been fatal had it connected.

Since most opponents Kenpachi fights have (much) less reiatsu than him, he's able to slash right through their defences regardless i.e. "With your imagination, you can't create anything I can't cut through".