Originally Posted by Gamabunta
I don't see anything else but naruto finally combining his and kyuubi chakra to be used in tandem as that jutsu minato wanted him to perfect. And we already seen this done without minato coming back to help. But i agree with Numi, he was brought back to confirm the kyuubi incident.
Why bring Minato back just to confirm an incident that Hiruzen witnessed as well. Also, why... when we've been shown the flashbacks through Kushina. Hashirama was brought back to (finally) provide the flashbacks to the Hashi-Madara battle at VotE. Hashi will probably crumble away once he sees the "will of fire" has been passed on to Naruto. Tobirama is probably (and hopefully) going to tie up the loose end of what happened with the Uzumakis. Hiruzen confirmed what Tobi and Itachi told Sasuke, so unless he's going to be around to battle Orochimaru, he's about to get wasted. And finally that brings Minato. Minato was brought back to show Naruto how to do "that" jutsu.
Kishi lauded Minato at the beginning of the manga to point of having fanboys and their nemesis argue over who's better between Minato and Hashi. The only remaining kage that faced Madara realized to put a flee on sight notice for Minato. And why also have Jiraya, the protagonist's mentor and father figure, talk so much about "that" jutsu. I seriously doubt it was adding elemental chakra to the rasengan, because Jiraya was a f'n sannin. Kakashi is child's play compared to Jiraya. I'm convinced we haven't seen "that" jutsu, and that is the sole reason for Kishi bringing Minato back.
Everyone has stated, who's going to teach Naruto the FTG? Well, it looks like it is going to the creator of that jutsu, and Naruto will probably expand on that one as well (which will probably be one of the biggest ass pulls in this manga, considering how many ass pulls have already occurred).
As shitty as they may be, Kishi is starting to tie up the loose ends. We're about the see the Hashi-Madara fight at VotE. Hiruzen confirmed what actually happened on the Uchiha massacre night. Naruto has (I'm assuming) perfectly synced with Kurama and passing out chakra like ecstasy at a rave. Imho, there are only two more loose ends left... what happened to the Uzumaki village and "that" jutsu.
Then again, maybe I'm giving Kishi too much credit and putting too much hope and aspiration for this series' climax.