User blog comment:Xilinoc/Ch. 545 - Blue Stripes/@comment-10630156-20130710052140

Maybe we misinterpreted what Nimiya said in Chapter 542 "To put in a Bit of his soul to put the icing on the cake" was him using his Human soul to fix Zangetsu. Maybe that is what zanpakuto are made of? anyway I don't think it is as far off as some are making it of Ichigo leaving the human world for good and becoming a Captain of the 13 if of course he has destroyed his Human soul in order to reforge Zangetsu