Pain is dependent on Madara because..

[Final Jutsu]

What if Pain is dependant on Madara.. reason being the Mask. The Mask might allow Pain to remain in this world.. I think the real pain might be rikkoudou afterall. His name was borught out of no where, and it would have more of an impact then someone like Nagato who has nothing to do with anyone.. Creater of the entire ninja world just reaks awesome/full of skill/power. The 3 great doujutsus might be intertwined afterall.. maybe the mask allows sharingan to act as somewhat of a rinnegan.. Elevate it to that level.. Also, maybe the Bijuu statue that pain summons is where rikkudou is being kept.. Once he is unleashed.. the real pain beings

Just a theory.. don't disect it too much.. just post if you like the idea or no ..

 

[Pain's rikudou!!]

Link removed

well, that's my theory on pain's identity and why I think pain is rikudou.
I know it's too long but it's worth reading, if it was true it would explain a lot of stuff.
also I never thought about the statue as rikudou's coffin, but it is possible that nagato having realized who he really is (as my theory describes) wants to be once again in his true body cuz maybe it holds all the secrets of the jutsus or something, that way he would be really strong.
also you could have made your theory longer and you could have explained why you thought such things.

 

[Final Jutsu]

Well.. the statue has Rinnegan eyes as well is one reason.. It seems possible.. but I dont know how likely.. might be giving kishi too much credit

 

[Spencer_Gator]

wouldnt be that bad I guess, the mask thing is kinda weird though. BUt Pein being Rikkodou or however u spell it is possible