The only way I see Sasuke winning this without the Bijuu, is if he mastered the Rin'negan to the point of mixing his Six Path techniques with his Perfect Susano'o.
- Logically, his Susano'o will be larger than it ever was because he is older and his chakra matured. I'd say his Susano'o should be about the size of his Bijuu Susano'o seen in the last fight, albeit lacking the Bijuu chakra.
- If he can mix techniques together with his Susano'o and Rin'negan, a Shinra Tensei amplified by his massive Susano'o would have capabilities never before seen in the manga. Scale wise, Pein's Chou Shinra Tensei was a village buster. Sasuke's base Shinra Tensei should be about as strong as that given how strong his chakra is, amplified by Susano'o it would be even stronger. Chou Shinra Tensei amplified by Susano'o should be tiers above that, well above what the Juubi even showed us with it's TBB (although this is all speculation on my part).
- This train of thought can also be applied to the other paths, like mixing Asura with his Susano'o for more limbs/weapons on it, using Human Path through Susano'o etc. We've already seen Sasuke use Amenotejikara through his Susano'o, so this should be possible.
- There is a huge possibility that Sasuke also possesses Limbo in his Adult form, as it was never stated that it was Madara's technique, and the data book supports that. Only those who naturally awakened it, and Sasuke is one of them to do so.
Put this all together, alongside Sasuke being faster, stronger, having stronger chakra, higher reserves etc. I don't see how Madara wins.
