kakashi and obito,naruto and sasuke will have the main role/s in defeating madara
Ok i know that this may sound a bit far-fetched the way i've put this but here's why i've come to this conclusion.
As we know before the flash backs started madara declared that he will fight naruto and be while obito fights kakashi and guy,we also know that obito blames kakashi for their former team mate rin's death, whether or not kakashi is completely responsible or not and why is yet to be revealed but it's clear to me that things will become clear and that it could turn out that maybe kakashi was placed under a genjutsu therefore meaning he wasn't aware of his actions until the genjutsu wore off, i say this because if you remember in chapter 604 when obito left madara's crib to help out his friends his sharingan started playing up and obito felt as if he was seeing something,it shows rin well at first you can't see her cause it looks like the image is obscured or whatever by something and as it begins to clear away you see rin who has blood coming out of her mouth and a shocked look on her face and a hand/arm through the left side of her chest(where the heart is) and as the image becomes clearer you see kakashi with his hand through rin's chest with chidori activated and rin who's been stabbed through the chestlooks horrified and say's kakashi and you could see that kakashi is visibly saddend and angry by what he's done and it becomes obvious that obito saw it aswell.
Don't get me wrong but from kakashi's reaction after stabbing rin through the chest with chidori i get the impression that he himself didn't know what he did till it was too late, from this i get the feeling that as zetsu said-kakashi and rin were surrounded by jonin level shinobi from the mist and that maybe either one of them placed a genjutsu on kakashi or and i could be wrong zetsu who was wrapped around obito as armour or even madara might have done something that both affected obito's sharingan and clouded kakashi's judgement cause obito see's what kakashi see's and viser versa cause they both have 1 half of obito's sharingan's and that whatever it was if it was a genjutsu might of caused kakashi to think he stabbed one of the mist shinobi with chidori and it wasn't until the genjutsu wore off that kakashi realised what he had done, this is shown by the reaction on his face and if i'm correct the trauma of kakashi possibly accidentally killing rin could be the reason why both obito and kakashi awakened the mangekyo sharingan, not only that but soon after if it is true that obito may have at some point awakened the rinnegan the trauma that obito suffered plus the senju dna infused with his body might have enabled him to awaken rinnegan, the reason i say this is because of when zetsu said: "if you put together senju and uchiha abilities....you might be able to obtain a power never seen before, but..............." then shortly after that obito saw what he though he'd imagined was rin's death, so with this i've come to the conclusion that what zetsu was gonna say to obito before he was cut off by obito is this:"if you put together senju and uchiha abilities, you might be able to obtain a power never seen before,but it comes at a price,to awaken this power you would either have to be on the verge of death or witness the death of a close friend or a loved one."
If this is true and IF madara did something to obito's sharingan which also clouded kakashi's judgement so kakashi thought he killed an enemy shinobi but actually killed rin the this would be a perfect excuse for obito to turn against madara and both obito and kakashi work together to fight madara not only that but because when both sharingan are together they can unleash their full power,both kakashi's and obito's sharingan abilities when they combine their abilities together will be unleashed and they'll be more powerful cause as obito said because they both have 1 of obito's sharingans together they would make a better combination meaning if they fight together, this would make sense cause if you remember when kakashi attempted to warp away obito using kamui, obito(as tobi) told him it wouldn't work against him, so i reckon that at some point during the fight between obito,kakashi and guy both obito and kakashi will realise that their sharingan abilities aren't having any affect on each other and obito will probably have a change of heart cause he'll figure out that kakashi wasn't to blame for rin's death and that madara was responsible, this will anger both obito and kakashi and they'll decide to combine both halves of their sharingans to fight madara, but they won't be the only ones,there's also naruto who knows that madara poses a bigger threat to the shinobi world than obito and well kurama who despises madara is willing to give naruto all he needs to defeat madara and do not forget sasuke, who didn't seem pleased that even though itachi ended edo tensei to sasuke's shock madara uchiha was also summoned and has broke way from the edo tensei jutsu's control meaning that when the other edo's dissappeared madara made sure to stick around and sasuke looked pissed and from his reaction and what he said when suigetsu gave him the scroll plus reviving orochimaru and declaring that he wants to meet someone/people to find out everything about the ninja world and about the uchiha and itachi a believe that sasuke has some sort of plan in defeating/getting rid of madara that involves fighting him, oh and before i forget in part 1 during the zabuza and haku arc sakura noted that even though they make out they hate each other etc both naruto and sasuke when working together make an awesome team, so heres the thing, as we know the war has reached it's climax and the final showdown has begun OR HAS IT!!!.
The war is far from over and the final showdown is yet to begin the alliance are on their way to help naruto and co,the 5 kage have been beaten to the brink of death by madara,tsunade's body is in two halves but she vows to save the other kages wheter or not this will lead to tsunade's death or not is yet to be known but the kages especially tsunade are in a very bad way,sasuke has yet to meet the person/people who know everything, we have yet to find out what the mysterious scroll contains which according to suigetsu,it could turn the tide of the war, sasuke would be interested in it's contents,and with the scroll team hawk can rule the world not only that but once sasuke meets whoever and finds out whatever what will he do with that knowledge and does it have something to do with the scroll if so what will the scroll be used for and for what purpose but one things for sure sasuke WILL go to naruto's battlefield.
So with it seeming possible that EVERYONE including the kages will come together at naruto's battlefield which don't get me wrong looks like the perfect place for an almighty final showdown in a battle to save the world i believe that yes everyone will get a chance to fight against madara and possibly get their chance to show what they're really made of but i believe that the main players who will have the biggest role in defeating madara uchiha and stopping the jubi are obito, YES obito and kakashi and naruto and sasuke,oh and before i forget kurama i say this because i truely believe madara is responsible for causing kakashi to kill rin and that obito and kakashi will want revenge, two halves of the sharingan coming together as one and unleashing their full potential and as for naruto and sasuke well naruto knows that madara must be stopped cause he's seen what madara is capable of(madara summoning 2 meteors to wipe out most of gaaras division) and that he poses a much bigger threat than obito, plus naruto is special, he is quite literally the will of fire incarnate,he posesses the will to never give up and as kuramas host and friend naruto will not let madara get his hands on kurama, hurt his friends or usesthe jubi to destroy the world and kurama well kurama wants madara dead and with sasuke in the mix especially if sasuke returns to the good side it will be a combo of kakashi with his arsenal of 1000 jutsu and perfect use of the sharing/mangekyo sharingan,obito more on less the same as kakashi plus the make a great team,naruto with his will of fire,guts to never give up,the power of kurama,sasuke with his ems plus maybe some sort of power up and his determination to avenge the uchiha by using all his hate against madara plus whatever knowledge he'll attain about the ninja world ,the uchiha and itachi etc and if it turns out like this boy would it be exciting.