Board Thread:Theories and Speculation/@comment-26844669-20171106001849/@comment-9782468-20171107033939

As far as I understand, the only upgrade Madara got from the original flesh he bit from Hashi was the Rinnegan, and that wasn't until much later in life.

He died with the Rinnegan, and therefore was revived with a fake Rinnegan (like how Itachi and Nagato were revived with fake eyes).

Kabuto revived Madara, but modified it so Madara would have his mind and eyes from when he died, but his youth and prime abilities as well. And, as @TheKillman said, the extra DNA from Hashi making the Hashi boob