First, let's tackle Kabuto:
We know that Kabuto was once working for Sasori for a period of time. However, his loyalties shifted towards Orochimaru. Kabuto has long been placed as an agent in several different roles before he began to become infamous and too well known - something he's recently stated that he wants to give up, since it's the major downside of Edo Tensei to him. He's a meticulous information collector, but he specializes in medical techniques - especially in altering the appearance of the dead, and other sorts of manipulation. This is why he's been Orochimaru's right hand man for such a lengthy period of time. This is important to keep in mind when we look into some of Orochimaru's motivations.
To get into Orochimaru's background, we'll need to look into a quick timeline of his actions:
• Orochimaru's parents are murdered.
• Orochimaru becomes sadistically obsessed with Kinjutsu and learning all Ninjutsu in the world.
• Orochimaru, Tsunade, & Jiraiya fight Hanzo, and then encounter Nagato - who Jiraiya is compelled to train after Orochimaru suggests to kill them.
• Orochimaru infuses Danzo with the First Hokage's DNA, as well as multiple Sharingan.
• Orochimaru conducts experiments on 60 children, using the First Hokage's DNA.
• Orochimaru fails to become the Fourth Hokage.
• Hiruzen becomes aware of Orochimaru's experiments, but lets Orochimaru escape.
• Orochimaru joins Akatsuki and partners with Sasori.
• (The Uchiha massacre takes place)
• Orochimaru fails to take over Itachi's body, losing his hand, and leaving Akatsuki.
• Sasori sends Kabuto to spy on Orochimaru, but Orochimaru turns him into a double agent.
• Otogakure is founded.
• Orochimaru is in Kirigakure, where he obtains Kimimaro after a massacre.
• (Kimimaro falls ill).
• Orochimaru finds and Curse Seals Sasuke during the Chunin exam.
• Sasuke is lured by the quest for power.
• Sasuke joins Orochimaru
• Orochimaru embeds himself into Sasuke's seal and feigns death.
• Orochimaru is released from Sasuke and defeated by Itachi.
• Orochimaru's preserved hand is attached to Kabuto.
• Orochimaru's chakra slowly begins to overtake Kabuto's body.
• Kabuto meets up with Tobi, leading the Konoha ninja there.
• Kabuto negotiates an alliance for Sasuke.
• Kabuto negotiates capture of Kyuubi Yamato for a single Zetsu for experimentation.
• Tobi acknowledges that Orochimaru's thoroughness in his investigation of Akatsuki:
- Knowledge Tobi's identity, Zetsu & his roles, First Hokage's DNA & weaknesses.
• Kabuto resurrects Madara, and shows full knowledge of his possession of the Rinnegan.
There are several exceptionally interesting points to look at here. Given the nature of his experimentation with Danzo, it's almost guaranteed that Orochimaru had access to Sharingan at that time, due to the sheer number that Danzo had implanted in himself. While some of them may have been added after the Uchiha massacre, I find it unlikely that this sort of creation would have been achieved without Orochimaru's direct assistance. We can also look into the fact that when given MORE than ample opportunity, he intimidates Kakashi, rather than besting him, proving that if his true motivation was simply the acquisition of the Sharingan for its copying capabilities, he could have achieved that long before now, so it's a bit of a Red Herring.
What's interesting to note is that Orochimaru is working towards very similar goals as Madara was, and it's likely that he had found out much hidden information about Madara in his early research into Konoha's Kinjutsu - we know that he had to obtain DNA from the First & Second Hokage's fairly early on, and it makes sense that he'd uncover information about Madara around the same time. This would fuel his belief in the abilitiy to unnaturally be able to extend his own lifespan to achieve his goal.
More than likely he also discovered the capabilities of the Sharingan to evolve into the Rinnegan sometime early into this investigation into Madara's secrets. With the rather extensive amount of research that he's done on the Sharingan via experimentation, he likely knows its full capabilities when transplanted. I would surmise that the Rinnegan evolution is only capable of being achieved through an Uchiha's bloodline, which would point to his need to attempt to take the bodies of Itachi & Sasuke, but ignoring Kakashi and Danzo's Sharingan entirely.
Given this information, I would surmise that in addition to extending his lifespan with the First Hokage's DNA, he wants the ability to copy any ninjutsu with the Sharingan, as well as being able to perform any element of Ninjutsu with the Rinnegan. This means that he had very similar goals as Akatsuki, however he is continually seen working against them, such as letting Team 7 live, in order to better the chances that they kill more members of Akatsuki. I would assume that this comes from a very different opinion as to how the power of the Sage of Six Paths should be used (Moon's Eye Plan), which brings up another point -
Orochimaru was within arm's distance of a Rinnegan user when they're in Amegakure. While it's possible that he just failed to notice it at the time, I have a difficult time believing that there wasn't something going on here, especially since they spent an extensive time being trained under Jiraiya, the opportunity seems to large for him not to have taken advantage of it. First, the events took place within the Second Shinobi World War - a war that is said to have been started by Konoha, where Hanzo and Orochimaru meet in battle. Second, during the Third Shinobi World War, Hanzo calls on the assistance of Danzo to help deal with Nagato. Third, Orochimaru is a member of Akatsuki where Nagato is the leader. Lastly, Nagato is said to have received his Rinnegan from Tobi, and the resurrected Madara displays a knowledge of Nagato as well. Each of these ties into things that Orochimaru was highly interested in, and very likely aware of, given his intricate spying network, and obsession with information.
So where does this put us?
This all plays in to a number of elements that make me think that Orochimaru may have been somehow involved with Tobi. Tobi's physical construction bears a very close resemblance to that of Danzo's arm, as well as the cloning process that Orochimaru later fled Konoha during. If Orochimaru needed an Uchiha's to obtain a functional Rinnegan, one might assume that he would use the First's DNA to create a body that could then copy Madara's chakra and physiology. With Sharingan, he would then be able to eventually unlock the Rinnegan, as Orochimaru had hoped. However, despite the fact that this seems ideal physically, We've seen that Tobi is unable to use any Ninjutsu aside from those granted by his implanted Sharingan (and later Rinnegan), making him essentially useless to Orochimaru if he wanted to use the body to master ninjutsu. If he was constructed as a clone in this way, he may have actually been nameless, and just abandoned, like most of Orochimaru's other research. After this failure, he would need to attempt to synthasize the First Hokage's DNA into a living being, because Tobi failed to fufil Orochimaru's ambitions as a host. This would lead to the construction of the 60 clones that he was banished from Konoha for abducting and experimenting on.
Whether or not Tobi begins acting on his own, or if he is being controlled from another source is unknown, but what's interesting is that Tobi's movements coincide with many of Orochimaru's own. The difficulty is attempting to pinpoint a timeline as to when Tobi was where. Perhaps earliest, Tobi is responsible for the attack on Minato - the man who took the position of Fourth Hokage from Orochimaru. Tobi is also seen controlling the Third Mizukage, a Jinchuriki who was responsible for vast amounts of bloodshed in Kirigakure, during the same period of time where Orochimaru managed to find the sole survivor of the Kaguya clan - Kimimaro. Tobi also aids in the Uchiha Massacre, eliminating almost all of the remaining Sharingan. Tobi's current ambition also lies with the Rinnegan, and the power of the Sage of Six Paths.
If it became clear to Orochimaru after being within Akatsuki that Tobi was somehow connected to the organization, he would almost certainly distance himself from it. This may have become apparent around the time of the Uchiha massacre, which coincides with Itachi's arrival, and likely this information becoming available to him. While he failed to take the Sharingan, he would begin manipulating other events into motion, and attempting to cause national destabilization. When the Shippuden arc takes place, we find that he and Kabuto continually allow Naruto to live, and even leak information to them about Akatsuki, in order to help stop it from achieving its goal. The only point at which a goal is struck is when Sasuke becomes available as a bargaining token, which brings up another important point: Orochimaru's end game.
If he hadn't been foiled by Itachi, Orochimaru would have managed to hide his existence inside the cursed seal, and take Sasuke over during a moment of weakness when he had managed to achieve the level of development that Orochimaru desired. This reinforces two things; one - Orochimaru isn't interested in JUST a Sharingan, and two - he worked a plan into play that explicitly removes him from being considered on the playing field of current dangerous opponents. If appearing to die, while remaining a threat was a game plan of his, it's assumed that Kabuto may be attempting to carry this through with his own actions. Joining Akatsuki, and using their forces to bolster the chances of obtaining all of the Biju, while simultaneously working Tobi into a position where all attention is focused on him would be perfectly according to plan.
Another point that seems to support this is the fact that Itachi is moving in to deal with Kabuto. Itachi's primary role in the manga has served to work against Orochimaru, and his knowledge of Orochimaru and the presence of the Edo Tensei jutsu is enough to make it imperative that he look into that's taking place. My question is whether or not Orochimaru would be able to escape another encounter with Itachi, and if so - how. I'm curious if Kabuto may be attempting to the one Zetsu he received to give Orochimaru a temporary body before he's overtaken, but the question then remains whether or not Orochimaru's chakra/physiology would be able to overtake a body like that, similar to what it's done with Kabuto.
The other thing to note about Orochimaru's return is that it would provide a strong bit of story motivation for Suigetsu and Jugo, since we've been seeing them on and off recently, and I'm not sure how else they fit into the current mix of events. It also brings Zetsu's role into question. We know that he's been recording both Naruto & Sasuke's important conflicts and monitoring their growth carefully, but we STILL don't know anything about him, or his motivations. Hell, he could even have been one of Orochimaru's experiments with the First's DNA. Either way, it's a lot of food for thought.
