Board Thread:Theories and Speculation/@comment-44142243-20200416151624/@comment-6769189-20200418214526

Maybe there was another user who had it back in the day. As it became a legend or whatever the detail of it not being a physical object became lost and Itachi either lucked out in that it manifested through his Susanoo. Or he somehow ventured into that inbetween life-and-death world amd snagged it up.