An Opening

is episode 379 of the Naruto: Shippūden anime.

Summary
As the Truth-Seeking ball attached to Minato's severed arm prepared to explode in a blinding light, a shadow clone of Tobirama quickly appears using Flying God of Thunder Technique, seizing the ball, teleporting to Obito whom he revealed had previously marked in his earlier attack, teleported once more to a safe distance for explosion, meanwhile the real Tobirama teleports to Minato after the burst. As Naruto praises Tobirama's use of his father's signature jutsu and addressing him informally, Tobirama corrects him saying Minato copied his moves and should be addressed as Lord Second, to which Naruto is left confused and Minato embarrased.

Elsewhere Madara engages Hashirama using the Perfect Susanoo and Wood Golem and Dragon respectively, as the rest of the Shinobi alliance look on in awe at the level their predecessors fought at, and feeling useless in the face of such powers. Shikamaru bolsters the alliance's confidence as he declares there will be a time their cumulative powers will be of need. Madara recalls their previous battle where Hashirama was victorious, declaring the outcome will be different in their current battle.

Obito emerges from the explosion, having been guarded by a shell formed of his Truth-Seeking balls. Minato states he will create an opening for attack using his Spiralling Flash Super Round Dance Howl Style Three justu, to which Tobirama reprimands his comedic style in naming jutsu. At that moment, Sasuke and Naruto advance, with Sasuke unleashing Ametarasu at Obito who easily deflects it with his staff as he saw Sasuke forming chakra in his left eye. Naruto says himself and Sasuke will create the opening while Minato and Tobirama launch the attack. Tobirama proceeds to mark Minato with his Flying God of Thunder seal, pointing out Shadow clone teleportation is to slow, as Minato reciprocates by marking Tobirama.

Naruto and Sasuke prepare a Scorch Release: Halo Hurricane Jet Black Arrow Style Zero attack as they charge at Obito, while Tobirama teleports behind Obito and Minato leaps in front of Naruto and Sasuke's attack. Confused by the tactic, Tobirama quickly grabs Obito, and as Minato is struck by the attack, Minato and Tobirama use the Mutually Instantaneous Revolving Technique to swap places, delivering the attack onto Obito, leaving Naruto and Sasuke smiling as they succeed.

Obito quickly disperses the flames with the Truth-Seeking balls, showing the earlier attack had no effect. Naruto and Minato comment on his supernatural power as Tobirama notices Minato's severed arm hasn't regenerated, leaving him to surmise the Truth-Seeking balls use Yin-Yang release which nullifies Ninjutsu, effectively making their reanimated bodies mortal.

Naruto proceeds to attempt at entering his Tailed beast transformation but fails as Kurama needs to gather more chakra and tells him to fight in normal mode in the meantime. Suddenly Gamakichi lauches a Starch Syrup Gun attack at Obito who blocks it with his Truth-Seeking balls shield, as he declares his summoning time period has expired and is about to disappear.

Minato attempts to appeal to Obito's former desire to become Hokage, but Obito deflects his comments by noting Minato's failures in that role, making it easier for himself to abandon his dream, believing Hokage is a pitiful role and causing Minato to feel regret and somewhat responsible for the events leading to Obito's defection, Kushina's death, Naruto becoming a jinchuriki and the current war.

In response, Naruto declares that Obito, who never became Hokage, has no right to make fun of the Hokage, and moresover has no right to insult his father who did become a Hokage. As he reveals a readied Rasengan, Tobirama rushes to his side and teleports himself and Naruto behind Obito, delivering a Sage Art: Rasengan to his back that produces a wound and sends him plummetting to the ground. Tobirama explains that from noticing Gamakichi's attack was blocked but not nullified, he, as well as Naruto, discovered Sage Jutsu was effective against Obito.

As the attack lands, Minato observes Naruto's success in achieving Jiraya's Sage Mode, and the Yim half of Kurama within Minato responds by commenting he feels somewhat inspired by Naruto's earlier speech and is not surprised how he convinced his other half to cooperate with him