Board Thread:Versus Debates/@comment-27664103-20160220225016/@comment-4646462-20160225172128

I think attaining some form of Asura's chakra (Hashirama's DNA, of course) is a shortcut to unlocking the Perfect Susanoo. Since Madara (stated in the manga, shown in the anime) has used PS before having eaten a piece of Hashirama and planting it in himself, it could just be that Madara, being a reincarnate of Indra, only needed to train and use his EMS enough (and build his resentment of the world to fuel his Uchiha Hate Chakra) to evolve his Susanoo.