Naruto vs. Mecha-Naruto

is episode 377 of the Naruto: Shippūden anime.

Summary
After Mecha-Naruto defeats Shikamaru, it intercepts the group by firing missiles, forcing them to take a detour into the forest again. Choji switches places with a transformed Akamaru and attacks Mecha-Naruto with his Human Bullet Tank technique, but Mecha-Naruto knocks Choji into a river, defeating him. Both Kiba and Akamaru use the Human Beast Combination Transformation: Double-Headed Wolf technique and attack with Fang Over Fang. Mecha Naruto counters this by transforming its own arm into a drill, which overpowers the duo and defeats them. The palanquin then falls over since no one was holding it in the front. Mecha-Naruto attacks again, but Neji stops it using the Eight Trigrams Palms Revolving Heaven technique. Mecha-Naruto tries blasting the rotating shield with lasers, but to no effect. It tries approaching the rotating shield, but simply gets knocked back. Mecha-Naruto then starts running around the rotating shield. After gathering enough speed, Mecha-Naruto breaks through the rotating shield and fires missiles at Neji, defeating him and Yamato. Kakashi decides to battle, showing his Sharingan, but after Mecha-Naruto shows its arsenal of weaponry, Kakashi finds it impossible to copy it and is left stunned. Mecha-Naruto fires missiles at Kakashi, defeating him. Mecha-Naruto then talks, wanting the Nine-Tails inside Naruto and attacks him with laser swords while siphoning Naruto's Nine-Tails chakra. After cornering Naruto, Gaara arrives and attacks Mecha-Naruto with a wall of sand. Gaara grabs Mecha-Naruto with a sand arm, but as he is about to crush it, Deidara shows up and begins taunting Gaara for being defeated in his battle against him, calling him weak. The Kazekage abandons his battle with Mecha-Naruto and chases after Deidara. Soon, Mecha-Naruto and Naruto are summoned into a giant snake's stomach, courtesy of Orochimaru who reveals that he created Mecha-Naruto but the Akatsuki stole it. After reprogramming Mecha-Naruto to obey him, Orochimaru orders it to take the Nine-Tails, but Jiraiya appears and summons Gamabunta, freeing Naruto from the snake's stomach. Orochimaru uses the Reversible Technique, causing the giant snake to swallow and digest Gamabunta and Jiraiya, defeating them. Mecha-Naruto battles Naruto again and overwhelms him, having nearly siphoned all of the Nine-Tails chakra, but Naruto refuses to give up not until he saves Sasuke. This statement causes Mecha-Naruto to change its programming (after Itachi installed an extra programming) to help Naruto and begins returning the Nine-Tails chakra to Naruto, much to Orochimaru's shock. Orochimaru attacks the duo, but Mecha-Naruto intercepts Orochimaru and bisects him in half. Not the one to accept defeat so easily, Orochimaru activates a switch, summoning a giant mechanical version of the Nine-Tails which begins destroying Konoha. Mecha-Naruto encases itself onto Naruto like a suit and both of them fly to Konoha to defeat the Mecha Nine-Tails, but their attacks have no effect. Mecha-Naruto decides to sacrifice itself to destroy the Mecha Nine-Tails by using the leftover Nine-Tails chakra it has. Mecha-Naruto ejects Naruto and uses the Tailed Beast Cannon, destroying the Mecha Nine-Tails and itself. The villagers celebrate Naruto victory and the episode ends with the village being comically drowned in Gaara's Sand Tsunami.

Trivia

 * Mecha-Naruto encasing Naruto into itself and how it functions as a suit is reminiscent to Iron Man.