Its just as likely to be Obito as it is Izuna, maybe even more so concidering that Obito's body/death was not 100% proven, yes the cave collasped on him and yes half his body was crushed, but his body was never recovered so there is not a 100% proof he died, where as Izuna's body was shown in what would seem to be a funeral, I dont think Izuna could fool madara by faking his death. and also Itachi did not kill shisui, He helped him commit suicide. BIG difference, and probably the act of helping him is what awakened his MS.
About shisui's its about the same, he's dead anyways and Itachi did it or just helped him commit suicide its almost the same he's dead anyway.. And Obito dude its 0 precent.. Obito LOST BOTH OF HIS EYES, HALF OF HIS BODY, HE WAS SUCH A LOOSER HE CANT EVEN DO A Fire ball jutsu at his age, HE WAS RECKLESS AND THE ONE WHO SEEM don't like to use his brain, all these facts are opposite Madara's.. He had both eyes, body, he was one of the most talented and strongest ninja in the history, also he was verry smart and all.. And Izuna, it might be him, we dont have clearly alot of facts, yes we saw his body, but it doesn't prove anything.. However lets take all thread together all theories and facts and there's the most posible that .
Madara splited him self into his self weakend version and he knew that the clone will revive him, bicouse he gave Nagato the rinnengan... Or just, he told clone to end a job and when done revive me with nagatos power of rinnegang, since clone failed, bicouse nagato bettrayed him, he was about to take a place of Real Madaras, till the last coffin cracked..
To those guys who said it was So6P,Jaraiya,the sages sons.I knew it was the real Madara Uchiha because there was no one else and the most logical answer to someone who could scare Tobi lol.This chapter was epic Naruto has really gotten awesomer
