Sasuke and Orochimaru (complete)
this is my final and concrete theory on this
the scroll that Suigetsu found is edo tensei. this why he tells Suigetsu that he still needs Orochimaru around, probably to show him how to use it or for Orochimaru to use it.
and when Orochimaru tells Sasuke that its a place he knows well, he seems to have this sinister look on his face, leaving me to believe that its probably Orochimaru's lair or the Uchiha burial grounds. and wishes to revive some people. perhaps to find out the truth about to coup or the reason why the Uchiha were a shunned clan. maybe he doesnt know what to believe because he's heard so many versions of it and wishes to find out the truth
and if at Orochimaru's lair, possibly a trump card for Orochimaru. bodies he kept hidden away for when the time came for their use
and finally screws over Jugo and Suigetsu to revive said people. if it indeed is two people or could possibly be more than two, but for my theory's sake its 2
when the time comes for this i believe there might be another flash back
seems to simple and obvious right, just remember Obito being Tobi, how simple and obvious it was
(off topic) was Kushina also sealed with Minato, if not then why not bring her back to mind F*** with Naruto, that could have been an emotional twist to the series, being forced to fight his mom and sealing her, if she isnt sealed away of course
anyways have a good night
(EDIT) - when he's speaking with Orochimaru he says "what Itachi was...."OUR" clan" the person or people he might revive is an or are Uchiha.
might be his parents because who else would you speak to about being who you should be and which actions to take.
and to argue against people who say how did Orochimaruo know who he was talking about. Orochimaru was able to hear everything from Anko's cursed sea.