Before you argue against me, remember to use actual facts presented to us in Manga and not your own fan fictions. Before arguing that Naruto is 4th, I will first prove that Naruto is not someone 4th Sealed Kyubi in. We know that the jutsu used by 4th to kill Kyubi (Death God summon (forgot the excact name)) is the exact one used by the 3rd in his fight with ORO. That fight clearly shows that it is a Justu used to kill target with your own life as the price. So It CANNOT be the case that 4th Sealed Kyubi into a Baby using that Justu as (I mentioned the sentence above) it is used to kill the targe with your life as the price. Therefore, 4th couldn't have sealed Kyubi into a baby (it is just not what his jutsu is supposed to do). So the Theory about Naruto as Demon container needs to explain how the demon is in him without saying that 4th put it in (since 4th didn't put it inside him). Only thing we know is that 4th applied the Death God Summon(DGS) Justu on Kyubi to kill Kyubi. From the ORO VS. 3rd fight we know that DGS kill s the target by pulling the target into the user's Stomach (the place where Seal is on Naruto) and then kill the user and target. Obviously the DGS wasn't successful since Kyubi is still alive. And it is clear said by 3rd that 4th used DGS on Kyubi. So the only conclusion we can come by combining all the above fact is that DGS failed due to Kyubi's power but managed to seal Kyubi. This implies that 4th who's stomach Kyubi was inside of turned into a baby or 4th's and Kyubi's esence combined producing a child who's body Kyubi got trapped into. Thus Naruto is 4th OR Son of Kyubi and 4th. If you disagree with what I stated expain to be where my logic goes wrong don't just make up your theory and state it as being correct. There is really no need to consider other theories when this is not proved wrong logically. I know that anyother theory must also use the same facts I used to make up the theory (Till the point where my logic falters) becasue this is all the information we are provided with.