heres your link....man seemed like i passed that chap. up bout 10 times looking for it.....i dont usually go through trouble posting link.....im lazy
You must be registered for see links
as for who is in coffin......hmm man i really cant guess to well
and madara heh......my theory is kind of out there
but here's the short version
madara (with injuries still left from hashirama fight, during time he was training itachi and shisui) had obtained obito's body......he combined the cells of hashirama with obito's body through years of oro/kabuto like experimentation......after body fully accepted senju cells he transfered his soul to new body and has continued to hone skills and get comfortable with new body
since he had transfered his soul he had lost his ems.....(w/o his soul his previous body crumbled to nothing like an edo after talk no-jutsu)
thus he uses nagato and sasuke to perfect their respective doujutsu only so he can take them for his own in the end.......well he hopes anyway
well thats the wack brain theory i came up with after putting together all i know about madara
his age and timeline
his doujutsu
looks/name play with obi-tobi
compatabilitie with white zetsu (tobi had his arm regenerated after battle w/konan)
anyway back to coffin........i have no idea who could make tobi react like that......and would have to be kept quiet or it would threaten madara