seph in north crater is real. others are just clones. one on boat is jenova controlling clone (exact clone not hojos crap) one in shinra hq is jenova controlling a clone to open door then taking on clone form. she actualling takes on the form of seph to make cloud think its really seph. cause jenovas just leading him to the real seph (forget why) (all from other people at other forums)

Oh and why use seph? cause that is a form cloud "knows" and wants to destroy. "settle the score" as said on midgar unfinished highway.
all to lead him to reunion.