First off. I am completely anti Madara. I think he was a terrible villain that only got so far far by being lucky when Kabuto summoned him through Edo Tensei. I am so glad he is not the final villain, because he didn't deserve to be. Considering the fact that he had no connection to any of the main characters, and wasn't relevant to the story.
Now to address the topic of the thread.
Madara doesn't need to have both his eyes, or any for that matter, to use Susano'o.
Izanagi changes reality.
Madara could make himself comeback at full power, and stomp exhausted Hashirama.