I guess the Reaper Seal isn't as permanent as it was made out to be.
Sasuke, Orochimaru, Jugo and Suigetsu sneak around Konoha to take the Reaper Mask from the Uzumaki Clan before going to secret Uchiha basement to start their business. Orochimaru wears the mask to become the Reaper and he controls the Reaper to slice open its own stomach. This releases four souls and also the arms Orochimaru that were sealed away, and this allows Orochimaru to perform Edo Tensei. Jugo sends his cursed seal power into Sasuke to force out the six Zetsu clones that Kabuto had put on Sasuke, and Orochimaru uses four of them as sacrifices to revive the first four Hokages from Hashirama to Minato. Orochimaru also takes over the body of one of the remaining Zetsus.
Just what we need, more zombies. This was a pretty interesting development in getting the first four Hokages back to answer some questions, but I don't like how Orochimaru just easily undid the supposedly "permanent" Reaper seal that the Third and Fourth had used. Orochimaru got his arms back, and now he has Kabuto's knowledge/chakra and the Zetsu DNA to further his powers, so once again he is a major threat to the world. I'm still banking on Orochimaru eventually trying to get Sasuke's body and get screwed by the Sharingan again for the final time. For now though, we'll see what sort of questions and answers will get thrown around during Sasuke's Q&A session with the four Hokages.
Now that the Hokages can be summoned by Edo Tensei, are we going to see Naruto fighting his zombie dad anytime soon?