Kip. 264: Secrets of the Reanimation Jutsu
Killer Bee attempts teaching Naruto to use the Tailed Beast Bomb, Gyuki briefly taking over to explain the risks of Naruto prolonging his Nine Tails Chakra Mode or using clones while in that state. When Naruto learns the Rasengan was modeled after the Tailed Beast Bomb, he undergoes training to figure out the right dosage of yin and chakra to use. Meanwhile, insisting he needs Anko alive to siphon Orochimaru's chakra from her, Kabuto complies with Tobi's insistence to explain the Reanimation Jutsu's workings. Tobi provides Torune and Fu and snaps the former's neck, Kabuto explaining the process while making incapacitated Fu into the vessel for a reanimated Torune. Kabuto adds that he cannot summon the first four Hokage whose souls are currently contained within the Reaper Death Seal, revealing that the jutsu can be undone by its user. Meanwhile, Ao detects a large number of White Zetsu moving underground with Kitsuchi and Kurotsuchi use their Erupt jutsu to flush them out. (Source: Wikipedia) Fourth Shinobi World War: Confrontation arc: (4/53)