Board Thread:Naruto Discussions/@comment-5110462-20140507152631/@comment-5110462-20140508094940

Elveonora is right, Madara got his Rinnegan almost at the end of his natural life-span, he summoned the Gedo-Mazou and latched himself onto the Mazou or maybe the tree that was grown using Senju DNA to increase his life-span, the dude had enough time to train, he passed on the knowledge of how to use the rinnegan to Obito so that he may groom Nagato for the appropriate moment when Madara needs to be revived