Read before posting.
So we know Yamato was captured with relative ease and stuck inside more hashi dna or something. Kabuto caught him and made him look fodder.

But besides that, he's stuck inside senju dna. What if He comes out even more badass than Madara?? If he comes out like Hashi on Uchiha steroids or something?? With all their combined efforts, could they triumph? This is the only suitable way I see Madara getting defeated