Madara and Obito continue fighting against Naruto, Bee, Kakashi and Guy.

Madara and Obito remain in contol of the battle and it looks bad for the opposing team.

During this, Tsunade is able to sacrifice herself to revive A, Gaara and Mei. She apologizes to Onoki and dies peacefully trusting in Naruto and anticipating seeing Nawaki and Dan again. She is also content with death because her reviving 3 of the kages will strengthen the newly formed shinobi alliance.

Gaara, A and Mei will be able to stand and will be eternally greatful to Tsunade and Onoki. They will be unable to fight right away due to severe injuries and lack of chakra. They will be helped back to the head quarters by whichever ninjas arrive on the scene.

Back to the battle between Madara\Obito\etc:

It will look bad for Naruto and team. They were not able to stand up to the task of winning this battle.

But, as manga timing always works, Sasuke will show up.

Sasuke’s goal in this battle is to take down Madara and Obito. I will explain a lot of my thoughts here in the spoiler.

Starting with the scroll Suigetsu found.

When Sasuke 1st got the scroll, he also learned that Madara was still around. [chapter 592]. He looked upset by that.

When Sasuke reads the scroll, he says – “This is it, the one who knows everything”

I believe here, Suigetsu is referring to the DNA of all the Uchiha who died during the massacre (or a way to get it for an edo tensei army of their own). Suigetsu is quite clear that if the full power of the scroll is used, Taka would have a good chance at being the most powerful organization. Also, this is exactly at the time when all the other edos disappeared so Suigetsu is probly thinking along those lines as well.

So Suigetsu sees the scroll as their own army to control.

Sasuke sees the scroll as a means to talk to the ones who knows everything, who I believe is HIS FATHER and MOTHER. (or someone else from the Uchiha clan, but pretty confident with his parents).

Another support for the edo idea, Sasuke needs Orochimaru to do it. (I don’t think Sasuke wants to learn edo, and definitely doesn’t want to do the sacrificial aspect).
Sasuke’s next line after saying he needs to use Maru is “the clan, the village… I’m going to meet the ones who know everything”

Once Maru is revived and Sasuke pretty much tells Maru his plan, Maru says “Why do you want to meet THEM?”

Right after that Sasuke is thinking about Itachi’s words to him, the main ones being “Sasuke, you may have been able to change father and mother… and the uchiha clan”

Orochimaru immediately notices that Sasuke is no longer the same as before because of his talk with Itachi. Sasuke is no longer driven by revenge, but he is still mad about Itachi being forced to suffer like that.

The last we saw\read of Maru and Sasuke was Maru agreeing to help and them setting off.

With Sasuke helping to take down Madara and Obito and other allied forces arriving to help, they are victorious.

The help from Sasuke was accepted by Naruto and others simply because they would have lost with out it.

At this point, Sasuke and Naruto once again begin to converse.

Kakashi and Naruto question Sasuke as to why he helped them and fought against 2 Uchihas.

Sasuke has his flashback of where he went with Maru to “meet them who know everything”

More thoughts in 2nd spoiler.

Simplifying the flashback. Sasuke and Maru went to a place familiar to Sasuke. More importantly, Sasuke’s parents were revived.

Sasuke had so many questions for them – JUST LIKE Naruto did with his parents.

Sasuke begins to hear all the things he needed to hear to fill the gap and answer questions.

I believe Sasuke’s parents will reveal that they were being manipulated by Obito who was claiming to be Madara.

Sasuke’s parents were not strong shinobi. In fact, none of the Uchiha were really that strong. (except Itachi and Shisui).

I am confident that the Uchiha clan as a whole would realize they were NO MATCH for the rest of the village.

So why did they decide on a rebellion? SIMPLE – Obito secretly met with Sasuke’s dad and persuaded him organize the Uchiha clan into causing a CIVIL war in the Leaf.

There are many possible reasons as to why Obito would do this, but the main one would have been retrieving the nine tails, secondly destroying the Leaf.

We know that Obito failed in destroying Kanoha and failed in retrieving the 9Tails thanks to Minato and many other shinobi who lost their lives.

Obito needed a new game plan to crush the Leaf and take Kurama (9 tails). And spurring the Uchiha rebellion was that new plan.

But Itachi ruined that plan! Itachi, many props here .

Itachi sided with the Leaf and tried his best to set it up so Sasuke could be a hero and save the Uchiha clans name.

Itachi convinced Obito to go along with only the removal of the Uchiha clan and Obito realizing Itachi would not allow for the village to die accepted. (this was basically Obito’s 2nd attempt to crush the leaf failing).

Anyways, back to Sasuke.

Sasuke learns that Obito and Madara were responsible for manipulating the Uchiha clan and for causing the 9 tails to go on a rampage (mostly Obito).

Recall that the 9 tails rampage caused the village to blame the Uchiha Clan because the shar has the potential to control the 9 tails…

Sasuke learns that Obito used the villages suspicions as well as other information to convince the Uchiha clan that they should defeat the Leaf for being walked all over.

Sasuke hears other info, but decides that he needs to Strike down Madara and Obito for putting their own clan through Hell.
Sasuke basically blames Madara and Obito for everything, but he is still pissed at the Leaf for asking Itachi to get his hands dirty instead of themselves.

This explains Sasuke’s reason for helping defeat Madara and Obito.

Stopping at this point because I got too many thoughts after what's already written!