Board Thread:Naruto Discussions/@comment-945885-20140709082448/@comment-1512913-20140715103748

@Man of Sin, LOL. Oro cultivated cells from Hashirama's remains. Cells produce chakra. And Hagoromo wasn't residing inside of Madara. Madara had Hagoromo's chakra and I suppose Hagoromo used it as a medium to manifest himself in physical world.