Naruto Uzumaki's Jinchūriki Forms

Naruto Uzumaki is the Jinchūriki of the Nine-Tailed Demon Fox. When Naruto taps into the demon fox's chakra, it increases every physical aspect of his body. He is gifted with near-limitless chakra and stamina, massive strength, increased speed, accelerated healing, and at times an almost impenetrable chakra shield. Naruto has unique access to the demon fox's chakra due to the seal that his father, Minato Namikaze, the Fourth Hokage placed on him. Minato states that he sealed the demon fox within Naruto because he felt there would someday be a need for it.

Initial Jinchūriki Form
By simply tapping into the demon fox's chakra, Naruto's body begins into it's initial transformation: The first signs to this are his eyes; his pupils become slitted and then his iris' will go from blue to red. Following this, his nails and canine teeth grow long and sharp. His blond hair will seem to become longer and spikier as they stand on end. Naruto's whisker marks will widen and thicken, adding to his feral appearence. While he can still stand on his own two feet, Naruto can move at greater speeds by maneuvering on all fours, in a manner not unlike the Four Legs Technique used by the Inuzuka clan.

Depending on how much chakra is unleashed, the red chakra is capable of glowing around his body in an untamed way. Naruto first reaches this form when Sasuke Uchiha was thought to be killed by Haku, overwhelming Naruto with rage and allowing the demon fox's chakra to leak out of the seal. Even though this is the weakest state of his Jinchūriki forms, it still increases Naruto's physical strength, to the point of being able to stop a massive snake going at incredible speeds, and healing well above most shinobi, even able to regenerate a lung pierced by a Chidori.

This form also increases his speed to such levels that nothing short of a fully matured Sharingan is able to track his movements. He can 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. Until special training from Jiraiya, Naruto could only reach this state through sheer rage or if his life was in imminent danger, but after having a inner talk with the demon fox, he is able to tap into the demon fox's chakra on his own or by simply telling the demon fox to give him some power.

One-Tailed Transformation
During Naruto's battle with Sasuke at the Valley of the End, the demon fox granted Naruto enough of its chakra that it leaks out of his body in a denser state. All the physical traits of the basic Jinchūriki form are present and slightly altered, including black rings around the more berserk-looking eyes, longer nails, and canine-like features. This form also comes with an additional bonus: the red chakra becomes a complete shield around his body, in the shape of a fox, complete with long ears and a tail, known as the demon fox's cloak or shroud.

When he is in this form, Naruto fights more like a beast; instead of using his fists, he uses his elongated, sharpened claws. Just like with his initial Jinchūriki form, while he can stand on his own two feet, Naruto can move at greater speeds by maneuvering on all fours. During Naruto's fight to keep Sasuke from defecting to Otogakure in the 'Sasuke Retrieval' arc, in the anime; while in his 'One-Tailed' state, Naruto is also seen as being able to use the Demon-Fox Cloak's tail like a Prehensile tail/extra limb, while hanging upside-down from a under cliffside stalactite in the Valley of the End.

Naruto's most powerful weapon in this state is the chakra itself and it appears 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 hits Sasuke before he could react. Since the chakra is sentient, it is extremely difficult, if not impossible, to predict, as Naruto was easily followed with the Sharingan, but the chakra was not. The chakra can also stretch far from the body, as when Naruto was shown using his "arms" to attack Sasuke from great distances. The chakra around his body grants him some measure of protection, enough that ordinary attacks like Fire Release: Great Fireball Technique will have no effect. The chakra can also act as a shell to help Naruto create a Rasengan without the help of clones, which being called the Demon Fox Rasengan.

Two-Tailed Transformation
After catching the Akatsuki member Deidara only to discover it was a Clay Clone, Naruto's frustration and anger at the death of Gaara caused him to slip into his two-tailed transformation. His physical characteristics matched the first two forms, but his red eyes and canines grew larger, and his lips acquired a black outline, similar to fox's. The chakra shield's only difference between the one-tailed and the two-tailed transformation was the extra chakra tail that formed.

While in this state, Naruto is still in control of his body, though to what extent is unknown. In the anime, he punches a tree, destroying it and a long line of trees behind it. He later attempts to attack Kakashi Hatake, who calms him down and brings him back to his normal self. The amount of chakra produced by the two-tailed transformation is so great that even Naruto's shadow clones doubled over in pain.

Three-Tailed Transformation
After Orochimaru revealed himself to Team Yamato and baited Naruto with news of Sasuke, Naruto went on a rage and first attacked him, progressing from a one-tailed to a three-tailed transformation in doing so. The three-tailed form looks similar to the two-tailed form, but with the demon fox's features becoming more pronounced. His eyes later become similar to the four-tailed transformation, but can return to normal.

The amount of chakra produced from this form is devastating, such that the air around him begins to sting others. This is the strongest form Naruto can reach and control. With the standard chakra shield's protection and attack power, a simple roar has the power to create a devastating sphere of destruction capable of destroying the Tenchi Bridge. In the second Shippūden movie, while fighting the Zero-Tailed Masked Leech, Naruto was able to use the chakra shield to mimic arms and wings for semi-flight.

Four-Tailed Transformation
When Orochimaru further taunted Naruto about Sasuke, Naruto, in a fit of fury and anger, slipped into the demon fox's grasp. The demon fox's chakra began to burn its way through Naruto's body, destroying his skin while rapidly healing it at the same time, and eventually covered his entire body in a mix between the demon fox's chakra and his own blood. Everything from his face to his chakra tails became completely solid, his eyes losing its characteristics and becoming empty glowing circles surrounded by a black mask of chakra.

In this form, the demon fox has complete control over Naruto's body, making him a mere endoskeleton for the demon fox's chakra, the chakra's internal support being Naruto's physical mass, with every living thing in its way a target. The four-tailed transformation has all the benefits of the other tails, with upgrades. With a simple wave of his hand, it can send a shock wave of destruction. The chakra shield, while being solid, is so hot that it can burn the skin on contact, and it's defensive power is so great that even Orochimaru's legendary Kusanagi couldn't pierce it, only bending it slightly. If Naruto is hit, the chakra itself can form another body, and strike back almost instantly. Finally, the demon fox also has the ability to charge a concentrated ball of chakra, consume it, and then fire it with such a force that it could destroy three Rashomon gates.

In the end, the four-tailed transformation is Naruto's greatest downfall. Because the demon fox's chakra is constantly destroying and creating new cells, it shortens Naruto's life, similar to Tsunade's Creation Rebirth. When the demon fox's chakra is finally repressed, Naruto needed immediate healing as the top layer of his skin was completely burned away. Naruto first slipped into this form when he was training with Jiraiya, who had used the toad key to "twist" the demon fox's seal. This weakened the seal and allowed the demon fox enough influence to produce the form, in turn almost killing Jiraiya.

Six-Tailed Transformation
During Pain's invasion of Konohagakure and after Naruto's failed attempt to defeat the Deva path, Naruto was left pinned to the ground when Hinata Hyuga challenged Pain in a desperate attempt to protect Naruto. Outmatched, Hinata was quickly dispatched, stabbed, and severely wounded by Pain's Chakra Disruption Blades. Infuriated and believing Hinata to be dead, Naruto lost control and exploded into his four-tailed transformation, which quickly slipped into a six-tailed transformation, skipping the five-tailed form all together. This form notably begins to show the Fox's physical self (first of which being the skeletal frame) manifesting into the real world.

In this form, the demon fox's bones begins to form out of the intense chakra around his body attached to the body with several thick chakra ligaments. The raw potency of its chakra is so great, that it completely rejects the First Hokage's Necklace's effects to repress it; the demon fox is shown to remove the crystal and crushes it. With its raw power, the demon fox is able to withstand Pain's Shinra Tensei, then reflect the attack back upon Pain himself. Unlike the four-tailed form, the six-tailed form is able to unleash a concentrated ball of chakra without first ingesting it. Without even being fully charged, the attack has enough energy to create a large crater next to an already destroyed Konoha.

Eight-Tailed Transformation
As the demon fox fought Pain through the six-tailed transformation, Naruto within his consciousness thought of Pain's plans for peace and pleaded for someone to help him with a response. Through his suffering, the demon fox tempted him to destroy everything in the world that hurt him and to remove the seal by saying that if Naruto gave his heart to it, then it would stop his pain. His influence caused the seal to "distort" and allowed the seventh and eighth tails to grow.

The eight-tailed transformation brings Naruto's body, like the previous forms, closer to that of the demon fox. This form is his largest so far, being about the same size as the demon fox, with muscle tissue beginning to grow on the bones from the six-tailed transformation, and the only things missing being the ninth tail, skin, and fur. The eight-tailed transformation is so powerful, it is capable of breaking through Pain's Chibaku Tensei with brute force.

Jinchūriki Chakra Control
In the event of the demon fox manifesting, Jiraiya gave Kakashi a special written seal tag that is to be placed on Naruto's body. This seal suppresses the demon fox's chakra and restores Naruto to his normal self. In addition, Yamato has demonstrated a technique that reverses Naruto's demon fox transformations, enhanced greatly by the First Hokage's necklace that Naruto wears. In anime, Naruto has shown that with enough will power, he is able to suppress the demon fox's chakra from taking over, if he acts early enough. However, the important factor to this is that the demon fox's chakra was responding to the vessel of its residual chakra. Sasuke has also demonstrated the ability to forcefully suppress the demon fox's chakra.

The seal, which keeps the demon fox within Naruto, was designed with a fail-safe attached to it. Minato made it so that if Naruto ever transforms into his eight-tailed form, the imprint of Minato will appear in his subconscious in order to prevent the seal from being broken. Furthermore, Minato can restore the seal to its normal state, but he stated that he can only do it once.

When Naruto encounters Nagato face to face, he is shown to be able to simultaneously use his Jinchūriki form and his Sage Mode. His eyes take on the appearance of a mixture of them both.