Naruto 519 spoiler

Status: CONFIRMED SPOILER

Sasori entrusted the Dad & Mom puppets to Kankurou, and asked him to pass them down the generations (because apparently, Sasori put a lot of "soul" in making those puppets, which was what made him strong). And after being convinced by Kankurou, Sasori disappeared in peace. Deidara was WTF and shouting to be released from the puppet which kept him prisoner. The ambush squad discussed on how they had found Edo-tensei's weakness.

Madara grew suspicious about Kabuto leaking their whereabouts to the alliance, because Anko veered too close to their hideout, and Kabuto was able to trace her immediately. Madara thought to himself that the one who was "using" the other was himself, not the other way round.

The next jutsu of Naruto was indeed about Bijuu-mode. Naruto tried and failed in turning (?) into the Kyuubi and became a little fox instead (lol). Apparently it was because Naruto and the Kyuubi lacked in bonds. Hachibi came out and explained to Naruto about the huge risk of using the Bijuu-mode.

The Bijuu-mode had the Jinchuuriki and the Bijuu draw chakra from each other. If the Naruto-chakra was drained completely by the Kyuubi, Naruto would die. He was also reminded not to use Kagebunshin in Bijuu-mode, since Kyuubi would immediately draw on all the chakras of the bunshins as well, causing immediate death. The chakra trade was supposed to be negotiated between the two, but Kyuubi didn't seem to be "that type" (figures). Hachibi told Naruto to give up on learning Bijuu-dama (the ultimate chakra blast of a Bijuu).

Naruto decided to use Rasengan on his usual mode instead (because he needed KBs for the jutsu), but his Rasengan split (!?). Bee was surprised seeing the jutsu, and asked who taught Naruto that. Naruto replied that it was taught by Jiraiya, and invented by the Fourth Hokage. Bee reacted upon the mention of the Fourth with excitement, and thought "What a coincidence!". (! potential plot twist!?)

Naruto complained about the usual Rasengan not working, and Bee talked about how the Bijuu-chakra had + and - chakra. The white and black ratio should be 8:2 to form a sphere (Greek to me).

Naruto continued training...