Originally Posted by avatar7
And I always wondered how come Madara is his young self when he was revived, instead of the old man he was when he died. Makes no sense, considering all other Edo Tensei ninjas were the same age as when they passed away. Either it's a plot hole or there is something that hasn't been revealed yet related to that.
Kabuto specifically stated that he altered Madara's Edo Tensei body.
Chapter 560 Page 3,
"Your Edo Tensei is special, you've been completed beyond what you were in your prime."
In other words, his youngest and strongest age, but with all the bells and whistles he gained after that point, such as Senju DNA and the Rinnegan, which he only obtained after he let Hashirama kick his ***.