Naruto Uzumaki's Jinchūriki Forms

Naruto Uzumaki is the third jinchūriki of Kurama, 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 Kurama's 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 Kurama's chakra, due to the seal that his father, Minato Namikaze, the Fourth Hokage, used on him. Minato stated that he sealed Kurama's Yang chakra within Naruto because he believed that Naruto would someday control its power to battle Tobi.

Initial Jinchūriki Form
By simply tapping into Kurama's chakra, Naruto's body begins its initial transformation. His blue eyes become red and pupils become slitted. 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 Kurama's 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 Kurama and demand some of its chakra. Even though this was the weakest state of his jinchūriki forms, it still increased Naruto's physical strength, and its healing rate was able to regenerate wounds that were beyond normal repair. 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 shock wave, 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 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, Kurama 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 Version 1 forms 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 tailed beasts, like Killer B, Naruto's transformations were almost always triggered by his emotional state. The more he was distressed, the easier it was for Kurama to manipulate him through its chakra; its control over Naruto usually corresponds with the number of tails grown. Naruto was 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 Kurama's chakra.

Naruto's most powerful weapon in that 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 Kurama's chakra on his body. Despite this, every advantage that the shroud gives Naruto increases in strength with each tail; for example, his roar that simply caused a powerful shock wave in his initial jinchūriki form, created an even more devastating wave 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 the three-tailed form was rendered ineffective, Naruto became even more enraged and instantly grew the fourth tail. Within his subconscious, Naruto passed through the gates of Kurama's cage and into its grasp. Kurama's chakra burns through his skin, forming a black sphere that was mixed with 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 was forced upon his body by Kurama through the weakened seal, which allowed the fourth to sixth tail to grow. Once the sixth tail grew, Kurama's skeleton began to form out of the chakra.

Unlike the previous forms where Naruto remained in control, Kurama 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 was transferred to Version 2 with massive upgrades; a simple wave of his hand was powerful enough to fire shock waves and the chakra wrapped around Naruto's body was so hot that victims were burned and poisoned by the foul chakra. Whenever Naruto was hit, a second body would form out of the chakra to attack instantly, and Kurama was able to fire a Tailed Beast Ball that was 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 Kurama 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 vaporising it, and also touched the Deva Path without burning him.

In the end, Version 2 was Naruto's greatest downfall. Because Kurama's 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 Kurama's influence within its chakra to leak out of the seal and produce the form, in turn almost killing the latter.

Partial Transformation
As Kurama 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, Kurama 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.

This form is his largest so far, being about the same size as Kurama, with muscle tissue beginning to grow on the bones from the six-tailed form. The only things missing from Kurama 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 Kurama's chakra. This is due to the hostility that still exists between Naruto and Kurama. When he attempted this transformation, he instead transforms into a miniature, comical version of Kurama. It was also shown that Naruto cannot maintain this form for very long, as it drains him of Kurama's chakra significantly.

Nine-Tails Chakra Mode
The is a form that Naruto gained after he separated and sealed Kurama 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.

With Kurama's 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. While in this form Naruto was able to surpass the speed of a fully charged A, who was the fastest shinobi in the world. While he can still feel pain, this form's chakra shroud gives Naruto a great amount of protection, regular swords are unable to pierce it and it protects him from extreme heat temperatures. Extreme Physical attacks do little damage, for example Han's power enhanced kick, was only enough to make Naruto's jaw ache despite its extreme strength.

Naruto can 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 Kurama's 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 Kurama's 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 Kurama's chakra, which allows Kurama to automatically drain Naruto's original chakra. If Kurama 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 Kurama 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 Kurama, implying that the untainted Kurama's 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 enemy White Zetsu, which indicates that the risks associated with this form are not instantaneous. Naruto was capable of staying in this form for an entire night and most of the morning during the Fourth Shinobi World War. However, an observant Eight-Tails notes that at some point Kurama had purposely stopped eating Naruto's chakra.

Trivia

 * Naruto's full nine-tailed form resembles his true form from the Naruto Manga Pilot.