I know everyone wants the Kages to go to the battlefield but one thing I've noticed about all the good guys who were resurrected is that they dont want to be a part of this war. Like Zabuza who pleaded with Kakashi to stop him no matter what it took, as his humanity was already dead. Until his consciousness was erased by Kabuto. However the Kages have their consciousness and I dont think they will want to be a part of the war. Its like passing on the will of fire. By not taking a part in the war the Kages will show that they have entrusted the village and the shinobi world in a whole to the next generations.
Even Orochimaru might not take a part in the war. He might want revenge from Sasuke for killing him but I dont feel that he will join or turn against Madara and Obito. And to be honest he is scared of Sharingan users which is why he wanted sasuke's body.
The question remains though that who will take on Madara and my answer would have to be Sasuke. 1stly Sasuke will set his goal to be to walk on Itachis path and protect the village. 2ndly Sasuke is probably the only one who can match Madara's power. Even Naruto doesnot seem to be able to have an upper hand against him if it were 1 on 1. Naruto on the other hand will defeat Obito though I think Kakashi will play a part in that aswell eventually getting himself killed.
After the war Sasuke will disappear and Naruto will let him so that Sasuke can be remembered as a war hero. And maybe in the future he will continue the Uchiha clans leagcy in some other country. Naruto will be declared as a sort of new version of the Sage of Six paths when he will combine Kurama and Hachibi into the 10 tails and become its Jinchuuriki. Poor guy wont be able to accomplish his dream of becoming Hokage though.
Thats'll probably be Hinata 
Even Orochimaru might not take a part in the war. He might want revenge from Sasuke for killing him but I dont feel that he will join or turn against Madara and Obito. And to be honest he is scared of Sharingan users which is why he wanted sasuke's body.
The question remains though that who will take on Madara and my answer would have to be Sasuke. 1stly Sasuke will set his goal to be to walk on Itachis path and protect the village. 2ndly Sasuke is probably the only one who can match Madara's power. Even Naruto doesnot seem to be able to have an upper hand against him if it were 1 on 1. Naruto on the other hand will defeat Obito though I think Kakashi will play a part in that aswell eventually getting himself killed.
After the war Sasuke will disappear and Naruto will let him so that Sasuke can be remembered as a war hero. And maybe in the future he will continue the Uchiha clans leagcy in some other country. Naruto will be declared as a sort of new version of the Sage of Six paths when he will combine Kurama and Hachibi into the 10 tails and become its Jinchuuriki. Poor guy wont be able to accomplish his dream of becoming Hokage though.