Everybody tried to figure out the connection between madara and danzou.
Tobi is madara for sure.
Cos he clearly admitted himself before..
And minato also stated that the main actor that control akatsuki and pein is the one who release the 9-tails fox beast, which is madara.
So there's no doubt bout tobi=madara.
But to come to a conclusion that madara=danzo, still needs lot of arguments and theories.
Madara surely knows how to not become old, since he should be dead, or at least way too old now.
I like the theory that madara might have taken obito's body, so that's why he's still quite fit for an old man.
And that's the reason why he only have the sharingan on his right eye, cos the left one had given to kakashi.
This theory support the similarity of the hair between obito, danzo, and tobi.
But this theory doesn't explain why must danzo cover his right eye..
To hide the sharingan? Nope..sharingan eye can easily transform to normal state.
Maybe his sharingan is special, so it need to be hidden so no one knows? Nope..madara in tobi mode also easily use his normal eye.
But madara is still strong enough...
He could easily tricked naruto and the gank from capturing him before, and that proves some skills..maybe the time space jutsu.
This jutsu theory also supports the explanation on how danzo and madara's ability to change their identity so quickly.
And this theory might explain several things.
Here's the brief story:
Madara has so much hatred to konoha. He use the new identity as danzo. He pretended to lose to sarutobi for the 3rd hokage to covered his madara identity (or he did really lose to sarutobi). He has an access to released the 9 tails in konoha. He knew itachi's power and high skills by his joining in anbu. Then he ordered itachi to wipe the uchiha's clan, cos he has a big plan for itachi and sasuke through akatsuki in the feature. Then he showed himself to itachi as madara to wipe his clan, so he can take itachi to join akatsuki. He acknowledge nagato's power and konan when danzo was in the group that ambushed yahiko. He knew orochimaru's dark side cos he live in konoha and ask him to join akatsuki once. He also knew kakuzu because kakuzu killed the 1st hokage (which he hate most), and madara is as old as kakuzu. He tried to ask oro once again to attack konoha through sai, whe naruto and oro had a fight. And all those years, danzo a.k.a madara living his life in 2 identities. And now he strikes back.
If this theory is true, then oh my gosh...he sure is the real actor here. I mean he's all the cause of everything happened here..starts from the early before konoha was build, until now. Wawww...i mean seriously..he's the whole thing, he should be the one as the main character. Naruto? He's nothing..
But again, all theories that explain madara=danzo always leaves a big question: how can be he's so that intelligent and smart, and make fool all shinobi in konoha for sooo many years, and no one ever realize it..not even the elders, sarutobi, minato, tsunade..and everybody? HOW COME?