This is what i think is going to happen
the 3 stages are set we know that, but this is what is going to happen in each of the battles.
Tobi vs Naruto, Gai and so on: As tobi thinks he has this thing won because it seems they are almost depleted out of Ki, all of the army arrives and rattle behind naruto, Naruto says his line we are united blah blah. Tobi makes a quick attack and takes BEE then says he will leave Naruto for now and decides to retreat to reassess his plan.
Madara Vs Kages: Madara is whooping their asses and at the same time they are almost all about to get defeated and die when suddenly before madara can deliver his final attack the coffin rises and traps him..WHAT??? yes that happens lol
Sasuke and itachi vs Kabuto: They start fighting and its an awesome fight but even as powerful as Kabuto is he is over whelmed by the Uchiha brothers after all sasuke with the EMS and Itachi with the MS is a bit much for anyone. and as soon as it seems that they are about to corner Kabuta, a coffin appears...Its Madara...Sasuke confident goes agains madara but he posses the rinnegan and its too strong for him. Itachi fights aswell but they are no match for Madara. They exchange awesome stories about the Uchiha and how they must join him but in the End The love for his brother is much more important then the pride of the Uchiha. Kabuto is killed but at the same time Itachi is killed sacrificing his life once more to protect his brother and the future. But not before telling sasuke something very important to him that will change Sasuke for ever. As Madara moves to finish sasuke, Sasuke's new EMS skill reveals it self and he is teleported away and is saved by this skill. He teleports to an orochimaru Hideout in the area and meets with his team and that Specific scroll.
Sasuke Gains the power in that scroll its probably activates some sort of power probably the rinnegan.
Ending Fight Sasuke goes to talk to Naruto and tells him he will defeat tobi and madara because he promised it to Itachi, but as soon as they defeat them he will fight Naruto like he promise. Naruto Decides he will help him and fight him.
Thats as far as i can see. Maybe Kabuto doesnt die but it seems to me that in the final battle Sasuke and Naruto will join forces to defeat Tobi and Madara. Sasuke will probably sacrifice his life in the end to defeat the Evil..In that way redeem himself and his clan and become a hero on konoha like Itachi always wanted naruto will become inturn the Hokage and Join all the villages in peace...THE END
What do you guys think?? Maybe give me ideas of what might happen between the madaras and tobi or if they will become one again or something crazy like that. It would be like DBZ and fussions and super power type stuff haha