Cool things we learned this chapter:
1) Madara may have had some form of eternal life with hashirama's power, but he did not have eternal youth. Also, he was tethered to the Gedo Mazo to stay alive, and could not leave his little fort without dieing.
2) Madara definitely gave his eyes to Nagato, and replaced his left eye with another stolen sharingan
3) Obito's Kamui power activated, he phased through the rock, and fell down to Madara's underground chamber. From there, Madara used Zetsu slime to heal him. (Obito did not immediately become evil and seek out Madara. Madara did not intentionally search for, find and save Obito. It was a chance meeting).
4) Obito is, at least at first, unwilling to help Madara and did want to return to the leaf village (but was unable because he too was limited in range and needed to stay close to the source of the zetsu slime)
New Questions that we have to be answered:
1) How did Madara stay in contact with Nagato, and therefore maintain control over Akatsuki during this time?
2) Would Madara have died if Nagato had summoned the Gedo Mazo statue away from Madara's hideout? Is that why Akatsuki didn't capture any Bijuu for the first few years of its operations, because the statue could not be used to seal the tailed beasts if Madara was attached to it?
2a) Is that what the "Immortal" Madara chose to die, so that Akatsuki could start collecting and sealing the tailed beasts?
2b) Did Nagato know that he was supposed to resurrect Madara at the chosen time? If not, what was Madara's plan to get resurrected?
2c) Was Madara's plan for Nagato to resurrect him, and then steal his old eyes back from Nagato in order to use the final technique? How would an elderly Madara without his EMS/Rinnegan eyes have possibly been able to defeat Nagato and steal the eyes back for himself?
2d) Why would Nagato have ever agreed to resurrect Madara when Nagato's plan (use the tailed beasts as a weapon to end war) didn't require Madara's help?
2e) Was Madara tethered to the Gedo Mazo when Nagato summoned it to fight Danzo/Hanzo? If so, why didn't Madara die then? If not, why did he ever need to be tethered to it?
2f) Why would Nagato agree to use the Gedo Mazo to keep Madara alive artificially? Once Pain was the leader of Akatsuki with his own goals and motivations, why would he choose to keep a weakened, elderly Madara alive?
2g) Why did Pain think that Obito was Madara, if he knew the real Madara was a weak elderly man tied to the Gedo Mazo to keep himself alive? Did Obito just appear one day with the mask on and say "I'm Madara, I got younger!"? Wouldn't Pain have been suspicious about that?
3) Obito seems like he doesn't want to join Madara, and tries to escape. So how does he turn from that into Tobi who is a psychopath
who follows Madara's mission?
4) How was Obito able to leave the chamber eventually, without his Hashirama/Zetsu slime dieing as Madara suggested?
4a) Why didn't Madara untether himself from the Gedo and leave his chamber, if Obito was able to do this supposedly impossible thing?
4b) Is this the origin of Zetsu, the black half stabilizing the white half and allowing it to leave the chamber?
4c) And if so, how is it that white Zetsu is able to separate from the black half without dieing?
So we did learn a few cool new things but on the balance we have a lot more questions that need to be answered, where the answers are not obvious.
