This is not necessarily for chapter 643, but for the upcoming chapters. I believe that Minato is soon going to die as he fights with the evil Kurama within him as he does with Obito. The evil Kurama will act up while Minato tries to convince him that his power is necessary for the fate of the world, but alas evil Kuruma will not listen. Minato will realize that his time has come to an end and will willing try to sacrifice himself to completely take down Obito in the process. Just before his wasted death that does not effect Obito a bit, Minato transfers the essence of the evil Kurama into Naruto who in turn will have his own disputes with evil Kuruma. As the good and evil halves join, evil Kurama will take over the now complete kyuubi resulting in Kurama forgetting the ralationship he share with Naruto, restarting the kyuubi-Naruto issue again. Overtime, Naruto will win helping Kurama regain his memories and gain much more power. With more power power and the anger that will cause Naruto to avenge his father's death, twice by the way, Naruto's willpower and chakra will significantly change the scale in the battle in favor of the Ninja Alliance.