Resonance (episode)

While Asuma trades blows with Kazuma, Sora rages through the Konoha ranks in a three-tailed cloak. Naruto moves to halt him, but the fox chakra sealed inside Sora stirs the genuine beast within Naruto, dragging him into a one-tailed state of his own. Yamato calls on his suppression technique, the method meant to calm a rampaging jinchuriki, yet it cannot hold, since the surge originates from Sora rather than from Naruto himself. Struggling against the change, Naruto is battered further and swells into a third tail.

Kazuma gloats that Sora has roused Naruto's inner demon, boasting that the real fox will now level the village. Pressed by Asuma on his reasons, he dismisses everyone as pieces serving a king and admits he would sacrifice anything for the goal, including twisting his own son into a living weapon. Sora's skin peels away as a fourth tail forms, and the same corrosion begins to creep over Naruto.

Refusing to surrender, Naruto scolds the fox for surfacing uninvited and drives a claw torn from Sora's bladed gauntlet into his own leg. The sharp pain drowns out the hatred feeding the beast, and his body reverts while Sora remains cloaked in four tails. Witnessing Naruto wound himself stirs something in Sora, who dwells on his isolation and the scornful adults around him, until Naruto's voice finally reaches him. The installment belongs to the anime-original Twelve Guardian Ninja arc.