Board Thread:Questions and Answers/@comment-2211792-20130312103855/@comment-2211792-20130312120934

I know it looks the same as it did back then. But we don't really know how exactly an asauchi changes when it becomes a zanpakuto. Maybe it doesn't change on the outside at all, but only on the inside (the zanpakuto spirit occupies it and imbues it with its powers).