On Chapter 503
There is something interesting about chapter 503 that I found while reading it on the day it was released. I don't know why I delayed so much asking this question, but at least here it is now.
After Minato essentially forces Madara to retreat, he goes to meet up with Kushina, and they begin talking about their family, that has just experienced the addition of a new member; Kushina tells Minato that if all three of them lived together, she would only be able to picture happiness.
But that's beside the point. After Kushina says she will die along with the fox to prevent its resurrection, Minato offers another idea - that both of them use the remaining portions of their chakra to seal into Naruto, so they can see him again when he grows up. Minato says to Kushina "...I'll lead the Nine-Tails away, with only a seal a non-jinchuuriki like me can use, the Dead Demon Seal!"
Coming on to my point. Kushina does not seem to like Minato's idea, but then Minato tells her the following, which seems to sway her into letting Minato seal the Nine-Tailed Fox into Naruto.
Now, my question is, what was the second thing Minato confirmed that night? He told Kushina that the masked man would be the one to bring catastrophe upon everyone, but that was only one of the two things he realized before summoning the Shinigami to seal the Nine-Tails away. Any thoughts on what this second realization might have been?