Okay, so, basically my theory is that as this infection goes on it will become more and more corrupted, until it looks like SIVA(Some players are already getting negative side effects from the infection). Then, there will be a cure of some kind, which will help those who are tired of the side effects. Then, either SIVA, or someone else, perhaps the Vanguard, will find a way to harness the final form of the infection, and use it in the SIVA pulse rifle we have seen so many times in the trailers. What do you guys think? Sorry about the wording here, I am kind of rushing right now, but, I hope you can still understand.