Excuse my spelling and grammar im on a tablet
Orochimaro dream is to have all the jutsu in the world, He also really wants Saskue's body. If you think back to Kabuto talking he said, Orochimaro and himself hypothesized about the outcomes of the tablet. Now Oro did say he knows a lot about Zetsu and helped with the research.Tthe research on the tablet is linked to the so6p. The sage is linked to the creation of jutsu. Now he took over a Zetsu body (Senju DNA) that should mean he has a link to the DNA..as he has alink to all with the curse mark. I refer to that because he created that jutsu. Since he created it im sure he had his reasons to make sure he could be revived threw it. He also created the body transfer ritual or jutsu. He took over a Zetzu body like he tried to do to saskue, But he succeded this time. The Zetsu would have saw all the past bodys Oro took over in the ritual Dimension..I am going somewere with this. Oro could switch between his real face and some other chick when he fought the 3rd so if he took over a zetzu body along with an Uchiha body he would in some aspects have there gentic make up and could possiably obtain shringan than rinnegan . or at least I think that's what he wants to do..Thus allowing him one step closer to getting all the jutsu
I am not saying im wright just a thought if im wrong could anyone fill me in on whats right I have been trying to figure Orochimaro out.