Board Thread:General Discussion/@comment-24065031-20131018111356/@comment-26420452-20131021180719

Katen Kyōkotsu is one spirit and functions so. Her being manifested in two swords is probably a result of being a playful one.

Probably, Ichigo's two blades will have different natures, one behaving like a proper Zanpakutō and the other behaving like a spirit weapon.