Sasuke's blindness and EMS
Its clear that Sasuke is being manipulated by Madara. So why is Madara sending Sasuke into a situation that he can't possibly win? He attacked the 5 Kages and 2 of the best shinobi in each of the village. I think I know the answer.
We have to look here first.
Naruto 403 page 17 | One Manga
Madara asks Sasuke if he is going to transplant Itachi's eyes. Its obvious that this is what he wants Sasuke to do, he wants Sasuke to achieve the EMS. Unfortunately for him, Sasuke says no. So what is Madara to do? Hes going to use Sasuke's hatred to manipulate him into a position where he MUST take Itachi's eyes.
Now here we have Madara purposely sending Sasuke to the 5 Kage meeting.
Naruto 453 page 01 | One Manga
There no way Madara could think Sasuke would be strong enough to kill all 5 Kages. Hes an intelligent man, and he obviously has different ideas.
Here we have Zetsu, under Madara's orders, tell the five kages that Sasuke is there.
Naruto 459 page 16-17 | One Manga
In my opinion, Madara is trying to force Sasuke into a corner. The only way for him to get out of this corner is to repeatedly use his MS techniques such as Amaterasu and Susanoo. By using these techniques over, and over again, Sasuke's eyesight is going to diminish.
I think Madara's ultimate goal in sending Sasuke to the 5 Kage meeting is to make Sasuke lose his sight. Sasuke is hell bent on getting his revenge. If he loses his sight before he is able to kill Danzo and the elders, he is going to become desperate. I believe that through Sasuke's desperation, Madara will be able to convince him to take Itachi's eyes, and thus achieve EMS.
So why does Madara want Sasuke to have the EMS? I'm thinking it may have something to do with the Bijuu statue....but my guess is as good as anyone else's.