So here is another "possible plot" post. I thought it sounded more unique and interesting than some of the other theories/plots I've read, so I thought I'd share it. I don't know if I should say spoilers, but I suppose just to be safe, people who don't want to know anything about the storyline before its release probably shouldn't read this (even though chances are in favor of it being not real... there is still a possibility that it is). Anyway, here was the post:
I am a student from Tokyo attending a university in US. Over the school break, I returned home to visit my family. The people of japan are crazy over advent children and there is talk about it everywhere, and many scripts in circulation. From my visit, I learned from reading some of the scripts (some are fake and distributed on the street for money) that the man in the wheelchair is the character sephiroth who has been disfigured all over from cloud. the regenerating power of the lifestream healed sephiroth, and because he is a demi-god, the lifestream could not hold him, and he managed to escape, while absorbing much of the power of the lifestream. the lifestream became polluted and weak, and since sephiroth took so much power, he let an outreak of disease that the lifestream has been protecting for all time.
since cloud had a pure soul, the lifestream turned him into a demigod as well, and released him to be the savior of the planet. the characters of the silver haired men are sadly clones, but much more powerful than the other ones. sephiroth was unable to create a decent clone before he entered the lifestream because he didn't have enough power, but since he was released, he transformed to be more powerful than the most perfect jenova.
the character of hojo returns to be a servant of sephiroth who helps him create the clones using the genes of jenova from her head which was recovered. but since he was disfigured, he took to hiding and had his new perfect clone do his bidding. at first there is only 1 clone, but towards the end, the clone clones himself to weaker but similar clones.
the children that are coming (advent children) are cloud and sephiroth. since they died while in the lifestream, the lifestream chose to release them as the children of the planet. since they were given the power of the lifestream, cloud, sephiroth, and all of the clones are immune to the sickness that effects everyone else.
many of the old characters reapppear living in the sick communities. cloud, like in the game is very unenthusiastic to do anything, but since he was exposed to lifestream, he can speak to dead people, mostly aerith. she tells him to come to her, so he returns to her church to become spiritually closer with aerith. there he learns what he must to do cure everyone. there is much confusion of what he must do exactly, but he must entirely destroy sephiroth with a weapon of the planet, which is later to be revealed as the buster sword that aerith must bless, but in doing so, will erase her from the lifestream so she can't be revived and cloud can never speak to again.
cloud is given a choice to cure the planet or to be with aerith again spiritually and physically. vincent, since he isn't human, helps cloud on and off, but spends most of his time doing his own business. there are many battles between cloud and the clones, but they all fall into one big fight where cloud fights all 3 of them. he decides to empower his sword, and defeats the clones with ease after he learns how to use the power of his sword. by this time, sephiroth has healed and looks entirely different. he appears to look like jenova but still human. he no longer has his sword and uses only magic to fight.
cloud is greatly overpowered by sephiroth, and in the final battle, is shot through his stomach with an energy blast. sephiroth comes to cloud, but with his last bit of strength, cloud pierces his sword through sephiroth's monstrous body. the sword has no immediate effect, and sephiroth laughs. cloud realizes that he failed and slowly begins to die. before he dies though, the sword unleashes a green light that turns into the lifestream that expands and swallows sephiroth. images of aerith can be seen in the lifestream, and once sephiroth is subdued, the lifestream makes an earthquake and dives back into the planet pulling cloud as well.
people slowly begin to feel better from the disease, however there is no word of cloud or sephiroth. the ending is a flashback of cloud letting aerith float in the lake, which pulls out to the lifestream and a transparent image of an unconscious cloud with a tear dripping down his face. the screen pulls back to see a bigger picture of the lifestream which shows a giant core which appears to be aerith's face.