Naruto Uzumaki's Jinchūriki Forms

Naruto Uzumaki is the third jinchūriki of the Nine-Tailed Demon Fox, and is gifted with its enormous supply of chakra and stamina, to which Kakashi Hatake estimated it to be a hundred times greater than his own when its influence is not suppressed. It also gives Naruto accelerated healing (recovering from minor injuries within a few seconds to major injuries within a day) and depending on the amount of the Nine-Tails' chakra he's using, Naruto is also given an increase in strength, speed, along with an increase in his healing factor to such levels that he recovered from a Chidori strike through his chest in mere seconds. At times, he is also granted a nearly impenetrable, fox-shaped chakra shroud. Naruto had a unique access to the Nine-Tails' chakra, due to the seal that his father, Minato Namikaze, the Fourth Hokage, used on him. Minato stated that he sealed the Nine-Tails' Yang chakra within Naruto because he believed that Naruto would someday control its power to battle Tobi.

Initial Jinchūriki Form
By simply tapping into the Nine-Tails' chakra, Naruto's body begins its initial transformation. The first signs of this are his eyes' pupils become slitted, and will change from blue to red. Following this, his nails and canine teeth grow longer and sharper and his blonde hair will grow longer and spikier, as it stands on end. Naruto's whisker marks will also widen and thicken, adding to his feral appearance. While he can still stand on his own two feet, Naruto can move at greater speeds by manoeuvring on all fours in a manner that looks similar to the Four Legs Technique used by the Inuzuka clan. Depending on how much of the Nine-Tails' chakra was unleashed, it was capable of glowing around his body in an untamed way, similar to fire. Until he achieved the Nine-Tails Chakra Mode, it was the only form which resembled flames.

At first, Naruto could only reach this state through sheer rage or if his life was in imminent danger, but after training with Jiraiya, Naruto learned how to contact the Nine-Tails and demand some of its chakra. Even though this was the weakest state of his jinchūriki forms, it still increased Naruto's physical strength (he was able to stop a massive snake going at incredible speeds), and its healing rate was able to regenerate his right shoulder and lung, pierced by Sasuke's Chidori. This form also increased his speed to such levels that nothing short of a fully matured Sharingan was able to track his movements. He could also use the chakra as a shockwave, sometimes merely using a roar or thrusting his fist out to send a rush of energy at his opponent.

When Naruto encountered Nagato face to face, he was shown to be able to simultaneously fuse his initial jinchūriki and Sage Mode forms together. His eyes took on the combined appearance of a mixture of them both. The exact capabilities of that form are unknown, but it was enough to completely resist Nagato's control of his Chakra Disruption Blades when it impaled Naruto.

Version 1
During Naruto's battle with Sasuke at the Valley of the End, the Nine-Tails granted Naruto more of its usual chakra, in which it began to envelop Naruto's body as a bubbling chakra-construct, taking on the shape of a one-tailed fox, which Jiraiya referred to as the. Naruto's one-tailed form had all the initial jinchūriki form's physical traits, but the black rings that surrounded his more berserk-looking eyes were also present. In this form, Naruto could use his elongated, sharpened claws instead of his fists, and run at greater speeds on all fours, making him more like a beast. The chakra itself in this form was noticeably denser than it was in its previous form, going from a gaseous state to a boiling liquid state. This boiling chakra increases in its potency as more tails grow, eventually growing hot enough to melt the ground he is standing on. The chakra produced by these forms was powerful enough to cause the shadow clones Naruto produced to double over in pain.

Unlike jinchūriki who have learned to control their beasts, like Killer B, Naruto's transformations were almost always triggered by his emotional state. The more emotional distress he was in, the easier it was for the Nine-Tails to manipulate him through his chakra, it's control over Naruto usually corresponds with the number of tails grown. Naruto is able to reach the third tail of Version 1 and remain in control over his body, but will become highly aggressive and dangerous due the negative influence of the Nine-Tails' chakra.

Naruto's most powerful weapon in this state was the demon fox shroud itself, and it appeared to have a mind of its own; when a strike that was meant for Sasuke missed, the chakra itself stretched off of Naruto's arm and managed to hit the latter before he had time to react. Since the chakra was sentient, it was extremely difficult, if not impossible, to predict, as Naruto was followed with the Sharingan, but the chakra was not. The shroud granted Naruto some measure of protection, as it could endure attacks like the Fire Release: Great Fireball Technique. Naruto could also use the shroud's chakra arms and tail as grappling hooks to either grab onto objects or enemies from great distances, and use it as a shell to help him create a Rasengan without the help of his shadow clones. However, the shroud was not without its drawbacks; after Naruto used his left arm for a number of attacks against Sasuke, it was left numb from overuse and the constant damage of the Nine-Tails' chakra on his body. Despite this, every advantage shroud gives Naruto increases in strength with each tail, for example his roar that simply caused a powerful shockwave in his initial state is strong enough to create a devastating sphere of destruction when his third tail grew. In Naruto Shippūden 2: Bonds, while fighting the Zero-Tails, Naruto was able to use the demon fox shroud to mimic arms and wings for semi-flight.

Version 2
During Team Yamato's mission to find Sasuke, the group found and fought Orochimaru, who continually baited Naruto with news of Sasuke. After third tailed form was rendered ineffective, Naruto became enraged and grew his fourth tail. In his mental world, Naruto fell into the Nine-Tails cage and into it's grasp. The Nine-Tails chakra burns through his skin forming a black sphere of demon chakra and Naruto's own blood until the sphere explodes, leveling the area around him and revealing Version 2. Unlike B, who has shown be be able to enter Version 2 with any number of tails, Naruto cannot achieve this form on his own, instead is forced upon his body by the Nine-Tails through the weakened seal which allows the fourth to sixth tail to grow. Once the six tail grew, the Nine-Tails's skeleton begins to form out of the chakra, bringing Naruto's body one step closer to becoming the Nine-Tails.

Unlike the previous forms where Naruto remains in control of his body, the Nine-Tails had complete control over Naruto's body, making him a mere endoskeleton for its chakra. The chakra's internal support became Naruto's physical mass, with every living thing in its way a target. . Every benefit of the Version 1 is transferred to Version 2 with massive upgrades; a simple wave of his hand is powerful enough to fire shockwaves and the chakra wrapped around Naruto's body is so hot that victims are burned and poisoned by the foul chakra. If Naruto is hit, a second body will form out of the chakra to attack instantly and the fox is able to fire a Tailed Beast Ball that is powerful enough to destroy three Rashōmon gates without losing momentum. In the anime, it could generate numerous bodies, almost completely altering its own form into an amorphous blob, with which it was able to attack from all directions, and create a twister with just one slash from its claw. . By the six-tailed form, the chakra was so intense that the Nine-Tails was able to resist the seal of the First's necklace and force Pain's Shinra Tensei back on him. Curiously, in the anime, the six-tailed form's demon fox shroud managed to swim through and direct a body of water with its own movement without vaporizing it, and also touched the Deva Path without burning him.

In the end, Version 2 was Naruto's greatest downfall. Because the Nine-Tails' chakra was constantly destroying and creating new cells, it shortens Naruto's life, similar to Tsunade's Creation Rebirth. When the four-tailed form was finally repressed, Naruto needed immediate healing, as his skin was completely burned away. Naruto first slipped into this form when he was on a two-and-a-half year training with Jiraiya, who had used the key to weaken the seal for just a short time. And for that, it allowed enough of the Nine-Tails' influence within its chakra to leak out of the seal and produce the form, in turn almost killing the latter.

Partial Transformation
As the Nine-Tails fought Pain through the six-tailed form, Naruto, within his subconscious, thought of Pain's plans for peace, and pleaded for someone to help him with a response. Through his suffering, the Nine-Tails tempted Naruto to entrust his heart to it so that it could destroy everything that was causing Naruto pain, thus distorting the seal and allowing him to go from the six tailed form to the eight tailed form.

The eight-tailed form is his largest so far, being about the same size as the Nine-Tails, with muscle tissue beginning to grow on the bones from the six-tailed form. The only things missing in the eight-tailed form from the Nine-Tails are the ninth tail, skin, and fur. This form is so powerful, that it was capable of breaking through Pain's Chibaku Tensei with brute force. In the anime, for the brief time it was unleashed, it breathed a large stream of fire, which burned through the debris of the Chibaku Tensei, making it look like a meteor shower falling down toward the earth.

Full Nine-Tails Form
Unlike some other jinchūriki, Naruto cannot fully transform into his tailed beast when using the full extent of the Nine-Tails' chakra. This is due to the hostility that still exists between Naruto and the Nine-Tails. When he attempted this transformation, he instead transforms into a miniature, comical version of the Nine-Tails. It was also shown that Naruto cannot maintain this form for very long, as it drains him of the Nine-Tails' chakra significantly.

Nine-Tails Chakra Mode
The is a form that Naruto gained after he separated and sealed the Nine-Tails from its chakra. He can access its chakra directly whenever he needs it without interacting with the beast at all. In doing so, he gains a chakra shroud that resembles the Sage of the Six Paths' silhouette. The colour of his eyes changes from blue to orange when he is in this form. Also, while the demon fox shroud is red and releases chakra as acidic bubbles, this form's shroud is yellow and releases chakra as flickering of flames. The chakra in this form also emanates light in darkness. This is most likely due to its colour.

With the Nine-Tails' power under his control, Naruto's strength is significantly increased to the point where he can push a fully formed Tailed Beast Ball through a multiple layered barrier. Killer B had trouble determining if Naruto's speed was from the Body Flicker Technique, as all he saw was a "yellow flash" when Naruto attacked Kisame Hoshigaki. He could also equal A's incredible speed, and ultimately surpass it even when he was travelling at the maximum speed of his Lightning Release Armor. This form's chakra shroud gives Naruto great protection, able to block three katana at once with out damage and withstand A's tremendous punches, but he noted that it would have been dangerous if A had gotten a clean hit on him. He could also survive hits from Rōshi's lava armour with minimal damage, even on a head on attack. Even when Han increased his speed and power with his Steam Armour, all he could do to Naruto's shroud was make his jaw ache a little despite a powerful kick. Naruto can also use the shroud's chakra arms to help him create new Rasengan variants, such as the Spiralling Strife Spheres and the Spiralling Absorption Sphere. The chakra arms give Naruto greater range of attacks as well as greater dexterity and manoeuvrability with his fighting style without the use of shadow clones. For example, Naruto is able to use the chakra arms to push himself off a platform, where he would normally have to dispel the technique and then create a shadow clone to use as a landing point in mid-air. He was also able to use the arms to extend his reach, instead of using shadow clones to propel him through the air. The power of his techniques have become so great that, unless they already have some inherent durability, such as the Third Raikage, resurrected ninja have a hard time regenerating.

Like his predecessor, Mito Uzumaki, Naruto also gains the Nine-Tails' ability to sense negative emotions, something that not even the best sensor-type ninja can do. Even while he was inside a chakra isolation chamber within the Falls of Truth, Naruto was capable of sensing intense negative emotions generated by Kinkaku. Due to having the Nine-Tails' Yang chakra in this form, Wood Release techniques will react to the chakra's life-giving properties and mature into full-grown trees within a matter of seconds, either by contact or close range.

However, using the Nine-Tails Chakra Mode is a huge risk. Naruto has to temporarily "shelve" his own chakra in order to use the Nine-Tails' chakra, which allows the Nine-Tails to automatically drain Naruto's original chakra. If the Nine-Tails manages to take all of Naruto's chakra, Naruto will die. In addition, the Eight-Tails advised him against the use of the Shadow Clone Technique, as the Nine-Tails would absorb every portion of Naruto's chakra even faster for each clone he makes. Because of this same reason, Naruto has to be careful about the amount of time he spends in this mode. The Eight-Tails also stated that there is a limit to how much chakra Naruto managed to pull away from the Nine-Tails, implying that the untainted Nine-Tails' chakra will eventually run out. Despite these risks however, once Naruto was on the battlefield, he deployed several of his shadow clones while in this mode to the different divisions to confront the White Zetsu Army, which indicates that the risks associated with this form are not instantaneous. He was shown to be capable of staying in this form for an entire night and most of the morning during the Fourth Shinobi World War, much longer than Sage Mode.

Trivia

 * Naruto's full Nine-Tails form resembles his true form from the Naruto Manga Pilot.