“Of course it is – as one of the mutant dozen. It would be far weirder if it weren’t weird, although I can’t claim to know anything beyond what that woman said. It wasn’t long ago that I learned of this crazy old coot Shikizaki. But Zetto the Leveler was made to be the hardest sword imaginable. People love to talk about how katana never bend or break or lose their edge, but as a rule, swords are expendable. To use them is to abuse them. But not so with the Leveler. It truly cannot break or bend, and thus can never lose its hard edge.”

Katanagatari Omnibus 1, Page 59