We know that Madara's revival with Rinne Tensei Rebirth was part of the Eye of the Moon Plan, and there are strong evidences to suggest that Tobi/Obito wanted to revive Madara all along but his plan got hampered by Nagato's betrayal. But there are also strong corroborative evidences that suggest Tobi/Obito didn't truly want to revive Madara, or at least, did not want to revive Madara after Nagato's death and wanted to use Sasuke as his replacement instead in casting the Mugen Tsukoyomi.
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Based on this conversation between Tobi and Zetsu, it is implied that Tobi wanted to revive Madara all along:
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But he lost the one who was supposed to cast the Rinne Tensei Jutsu: Nagato
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And Obito himself apparently doesn't want to cast it himself, since in doing so would result in his own death:
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Many assumed that Obito's statement concerning Sasuke synching with the Mazo has to do with him being Madara's replacement in the Eye of the Moon Plan:
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But there is also the interpretation that what Tobi meant by synching was actually in reference to Bijuu extraction:
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That Tobi intended Sasuke to synch with the Mazo to facilitate faster Bijuu extraction process.
But Tobi could have intended Sasuke to serve a double purpose:
a.) Sync with the Mazo (Bijuu extraction), and implant the Rinnegan on him to cast Rinne Tensei to revive Madara
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or
b.) Sync with the Mazo (Bijuu extraction),and have Sasuke replace Madara altogether in casting Mugen Tsukoyomi (EMS)
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Like I said earlier, it is plausible that Obito didn't intended to revive Madara at all based on this panel:
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If we work on the premise That Obito didn't intend to revive Madara, then he must have needed Sasuke for the Mugen Tsukoyomi.
It is rather heavily implied that Tobi/Obito himself does not have Tsukuyomi:
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Obito not having Tsukoyomi is a form of Madara's insurance that even if Obito didn't like/trust him, he still needed to revive him because Madara was the only one who has Tsukuyomi at that time:
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But Obito could've found a loophole in Madara's insurance:
In the person of Sasuke who also had Tsukuyomi:
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But there was a problem, Sasuke's Tsukuyomi was still weak:
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So Tobi Sasuke to have EMS:
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Sasuke didn't initially had/wanted to transplant Itachi's eyes in him:
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So Tobi had to pressure Sasuke in obtaining EMS.
Zetsu (under Tobi's orders) tipped the Five Kages of Sasuke's presence in the summit location:
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That resulted in Sasuke getting beaten up by the Kages
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So after Sasuke got beaten up, he finally decides to acquire Itachi's eyes and get EMS
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Tobi's plans for Sasuke is proceeding as intended.
But then he appeared:
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And did this:
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Kabuto Edo Tensei'd Madara
In the event that Madara breaks free and finds out Tobi intended to replace him with Sasuke, Tobi will be in serious trouble.
That's why Tobi was interested in knowing how to stop/unsummon Edo Tensei:
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Of course Kabuto lied about the correct hand seals in unsummoning the jutsu.
And eventually activated Edo Madara:
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Which visibly infuriated Tobi:
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And to make matters worse Sasuke escapes from the hideout:
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Then Madara finally breaks free from Edo Tensei's control:
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And Obito did not seem pleased to meet him:
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So Obito is now stuck with two fatal options:
a.) He doesn't revive Edo Madara with Rinne Tensei, but the Juubi will break free from their control, thus the Eye of the Moon Plan (their goal) will fail.
or
b.) He revives Edo Madara with Rinne Tensei so that Madara could become the Juubi's Jinchuuriki but he would die in the process of using Rinne Tensei.
So which is more important to him? his (Obito's) life, or his ideals? Is Obito willing to sacrifice his life for the ideology he and Madara shares, we will find out in the upcoming chapters.