Power

Produced to commemorate the Naruto: Shippuden anime reaching five hundred episodes, this arc runs from episode 290 to 295 and slots into the middle of the Fourth Shinobi World War: Confrontation. Tsunade dispatches the reformed Team Kakashi to a place called The Hole to look into the slaughter of Tonika Village, carried out by Kabuto Yakushi and the shinobi he has revived through Impure World Reincarnation.

At The Hole, the team clashes with Kabuto, who uses the site's peculiar water and tiny snakes to spin off a genetic copy of Hidan and fields a squad of reincarnated ninja. During the fight Naruto swallows some of the snakes without realizing it. The village's few survivors, the orphans Leo and Miina among them, have fled to nearby Hacho Village under their teacher Dokku, carrying two secret steel bars entrusted by the dying village head.

Those bars are keys to the Ama no Hoko, a world-threatening power long sealed inside The Hole as seven sounds called the Saezuri. The mute, traumatized Miina senses the snakes writhing inside Naruto and forces them out, whereupon they fuse into a four-tailed clone of him that attacks everyone, beyond even Kabuto's control. As reinforcements from the Konoha 11 arrive, the clone drains Naruto's chakra, swells in size, and lays waste to Hacho Village.

The mastermind proves to be Disonasu, the Hacho leader, a former Akatsuki subordinate who hired Kabuto to wipe out Tonika so he could claim the Ama no Hoko and avenge his defeat by Pain. He activates the Saezuri to raise the power from underground, and the runaway clone mutates into a hydra-tailed monstrosity.

Pushed to the brink, Naruto nearly surrenders to the Nine-Tails before Minato's voice steadies him, letting him wield a partial Tailed Beast Mode. When the fox starts to seize control, Miina's melody breaks through and returns him to himself. Recalling the tune, Dokku alters the Saezuri's sounds to shut down the tower, and Naruto destroys his clone as the Ama no Hoko sinks back into the earth.

Disonasu, who had survived crippled, is finished off by the reincarnated Tonika village head, which also lets that soul rest. Letters later reveal that Dokku and Shiseru married and adopted the orphans, the Saezuri was resealed, and the dead were laid to rest, while Kabuto slips away, shedding his skin to reveal the white serpent growing beneath.