It appears to be a polearm that can change into something akin to a three_section_staff (post #949683). A "sectional polearm", if you will. Perhaps there should be a tag for sectional weapons that would include three section staves, sectional polearms, and (maybe) nunchaku? Sakura_Kyouko and her polearm would probably populate the "sectional polearm" bit fairly well.