To combine all the 9 tailed-beasts to form the parent 10 tailed beast and to use its power to cast a permanent genjutsu on earth by using the moon and hence, getting total control over it.
According to the information, the real Madara is Obito Uchiha
kisame assumed madara was the fourth mizukage , after all fourth mizukage yagura was actually manipulated by madara/tobi ... so you can assume that madara was the real mizukage and yagura was just a puppet ...
the REAL Madara Uchiha
Tobi is really Madara Uchiha
The real Uchiha Madara
He's hiding his identity because he wants people to believe he is the real Madara Uchiha, so he's hiding his real face under a mask.
he said that he had an enormous amount of chakra so he could survive for very long
the leader of the akatski is Tobi Tobi, is the name used by the leader of akatsuki but his real name is Uchiha Madara.
It seems the person everyone believed was Madara Uchiha, is a fake, as the real Madara Uchiha's dead body was in Kabuto's possession, and he has been revived by the Impure World Resurrection technique.
Yes. The real Madara Uchiha discovered the link between the Sharingan and the Rinnegan, before his death. The Rinnegan is an advanced form of the Sharingan, and he was able to awaken that ability.
He didn't become Madara, he is Madara.
Tobi shows his real face in episode 475 and reveals his identity as Madara Uchiha