Ten-Tails

The is the combined form of Kaguya Ōtsutsuki with the Shinju to reclaim the chakra inherited by her sons, Hagoromo and Hamura, and tied to the legend of the Sage of the Six Paths and the birth of shinobi. A menace to life in the distant past, the Sage and his brother managed to defeat the Ten-Tails and harness its power to usher humanity into a new era. At the end of his life, the Sage split the Ten-Tails' chakra into the nine tailed beasts so that its power could never be used against the world again. Centuries later, its revival became the objective of Madara Uchiha and the Akatsuki. The world of ninja united in opposition of this ambition, resulting in the Fourth Shinobi World War.

Background
Long before the founding of the hidden villages, during an era of endless wars between mankind, the Shinju, a tree revered as a deity, bore a Chakra Fruit once every thousand years. Although it was forbidden to consume the Shinju's fruit, it was eaten by Princess Kaguya Ōtsutsuki, who used the power it granted her to end the wars plaguing the lands. Some time after this, Kaguya gave birth to two sons who became the first humans born with chakra. Later, deciding that her children's chakra was rightfully hers, Kaguya fused with the Shinju into an entity that became known as the Ten-Tails, which ravaged the land in an attempt to obtain said chakra. However, because Kaguya's true motives were not realised, it was instead believed that the Shinju itself had taken on the form of a monster in an attempt to regain its lost chakra.

In the final duel between the Ten-Tails and Kaguya's sons, Hagoromo and Hamura, they managed to defeat the beast and sealed it within Hagoromo. This act, along with many other great deeds throughout his lifetime, resulted in Hagoromo becoming revered as the "Sage of the Six Paths". However, knowing that his death would unleash the Ten-Tails back into the world to continue its rampage and reclaim the chakra he had spread among humanity, Hagoromo separated the monster's chakra from its body and used his Creation of All Things ability to create the nine tailed beasts. Hagoromo then used Chibaku Tensei to seal the Ten-Tails' husk in what would become the moon, during which led to the creation of Black Zetsu to serve the will of Kaguya.

Centuries later, the Rinnegan would once again manifest itself in one of Hagoromo's descendants: Madara Uchiha. With his new power, Madara summoned the empty vessel of the Ten-Tails back into the world and named it the Demonic Statue of the Outer Path. Joined by Obito Uchiha, who continued his work after his death, Madara devised a means to reunite the Demonic Statue and the tailed beasts back into their original form so he could use the Ten-Tails to enact his life-long ambition: the Eye of the Moon Plan.

Personality
The Ten-Tails follows Kaguya's will to reclaim the power that had been taken from it and as Kurama noted, this form of singularity in its mindset made it impossible for those to sense it through means such as detecting negative emotions or even chakra due to its vast power. Individuals in Sage Mode are best able to gain some sense of the beast's power, and even then it appears immeasurable and overwhelming; Kurama likens the Ten-Tails to be an innate force of nature. However, due to Kaguya's presence within it reacted to seeing the presence of the tailed beasts' chakra inside Naruto and the image of Hagoromo by gathering chakra and strengthening itself.

Appearance
The Ten-Tails is a brown creature of titanic size; one of its hands is bigger than any of the tailed beasts. Its single eye, which takes up most of its head, is a Rinne Sharingan containing several tomoe. Silhouetted prior to its introduction, the Ten-Tails was depicted as a cyclops-like humanoid with long, spike-like protrusions on its back and ten tails. In a later appearance, the Ten-Tails' look was a bit more "crass", the spiky protrusions on its back were much higher, resembling a conch shell, and its tails appeared to be bushier.

Upon being revived in an incomplete form, the Ten-Tails possessed a grotesque bulb-like body with spiky protrusions growing out of its back and a wide, cavernous mouth with multiple rows of sharp, pointed teeth, as well as a spiked chin. It had long arms and clawed hands, but no visible hind-legs. It also had dark veins similar to those of a plant all over its body, and the endings of its tails resembled leaf buds, which unfurled as the beast matured.

After further maturing, the Ten-Tails took on a more humanoid form. Its bodily proportions were very elongated and emaciated with a twisting neck, yet it retained the spiked bulb from its previous form on its back. The beast possessed visible legs, which it used along with its right arm to stand, as its left arm was missing from the elbow down. Its facial appearance changed greatly, growing a single ear on the right side of its head, while its mouth, which now contained straight teeth and a nostril, moved to the left side. Several horns formed on various parts on its head with two underneath its chin, beneath its eye. The monster's tails also became hands similar to the chakra arms formed by jinchūriki.

As it continued to mature, the Ten-Tails gained a more muscular, healthy appearance, grew a complete left arm, giving it the ability to form hand seals by clapping its hands together, and began standing on its hind legs once more. After gathering more chakra, it evolved further by assuming an even more muscular form, with its horns growing longer and the bulb on its back becoming much smaller. In this form, the Ten-Tails could open its mouth wide to reveal a rafflesia-like attachment when producing a Tailed Beast Ball. When Hagoromo and Hamura encountered the Ten-Tails, it strongly resembled this form, albeit with a bloated appearance and additional spikes on its body.

When the Ten-Tails was recreated by Obito, it appeared as a tree, much like the original Shinju, with a tall, straight trunk, and retained its eye. This form of the Ten-Tails was initially referred to as the Shinju by Gyūki, but the Shinju was shown to be a separate entity altogether by Hagoromo, and this tree form was later confirmed to be the Ten-Tails.

When Kaguya Ōtsutsuki lost control over the tailed beast chakra inside her after being hit by Naruto Uzumaki's attack, she unwillingly became a non-humanoid Ten-Tails that manifested as a bloated, rabbit-like form, with the heads of the nine tailed beasts growing from various points on its body. This chakra-based form of the beast retained Kaguya's Rinne Sharingan as well as its ten arm-like tails, which it used to absorb any chakra it came into contact with.

Abilities
As the original form of all nine tailed beasts, the Ten-Tails was said to be the progenitor of everything that exists in the world. A god that created countries, it has the power to swallow oceans, split the land, and carry mountains. Kurama admitted that it alone wouldn't even stand a chance against the Ten-Tails, and stated that the Sage of the Six Paths told them that its revival would result in the end of the world. When Naruto Uzumaki attempted to gauge the power of the Ten-Tails using Sage Mode, he was overwhelmed by the vastness of the beast's power, which Kurama noted as immeasurable. Gyūki stated that if the Ten-Tails was allowed to reach its final form, then there would be no chance of defeating it.

In its first form, Madara and Obito could control the Ten-Tails by attaching to it using tendrils that could be extended from its body. To properly control it in its second form, however, they had to reinforce their connection using Hashirama Senju's DNA, and Madara suspected it would be impossible to control the beast in subsequent forms without becoming its jinchūriki. While connected to the beast, Obito used it as a medium for his Wood Release: Cutting Technique. According to Kurama's Yin half, there is a side effect to the Ten-Tails being extracted from its jinchūriki; while the tailed beasts' removal will not put its host in mortal danger, due to the Demonic Statue of the Outer Path itself having a strong life force, it will leave the individual completely paralysed for a time.

In its tree form, its roots can extend and capture enemies as large as tailed beasts. When its bud blooms and its eye within is revealed, the Infinite Tsukuyomi can be activated. Those who are placed under said genjutsu and attached to the roots of the Ten-Tails' tree form (or attached to the Shinju's roots when Kaguya casted the Infinite Tsukuyomi) are gradually reduced to shells of their former selves, ultimately becoming White Zetsu.

Chakra
Considered to be the source of all chakra, the Ten-Tails possesses massive and overwhelmingly foul reserves that are potent enough to bring total despair and destruction to the world. With each transformation, the beast's chakra increases significantly; after achieving its second form, its chakra completely warped the shape of the Sensing Water Sphere at the Allied Shinobi Forces' Headquarters into two connected spheres. The Ten-Tails can also gather massive amounts of chakra to use for various techniques of large-scale destruction. In its tree form, it can use its roots to absorb chakra from captured enemies to the point of decimating them almost instantly.

Physical Prowess
Even in an incomplete state, the Ten-Tails possesses immense physical strength and is remarkably fast, despite its tremendous size, as it could attack both Naruto and Killer B before either of them could react. It casually flicked back a Tailed Beast Ball with one finger, and could cause a massive-scale earthquake, upturning large portions of land, by simply slamming its hand on the ground. The beast has extreme durability and can remain unfazed even after sustaining massive damage, with a combined Tailed Beast Ball from both Gyūki and Kurama not harming it. As noted by Obito, the Ten-Tails can even withstand the backlash of its own Tailed Beast Ball fired at point-blank range, as shown when its attack, along with Gyūki's, detonated inside of its body, causing it to briefly inflate before shrinking back down largely unaffected. Even wind-enhanced black flames only seemed to irritate the beast without doing any lasting damage, despite Amaterasu on its own being able to neutralise Gyūki.

With a single swipe of its tail in its initial form, the Ten-Tails can create a shockwave powerful enough to tear up the landscape around it. In its second form, the beast's tails become elongated arms, which effortlessly broke free from the various restraints created by the Allied Forces. The beast seems capable of freely expanding the length and thickness of these tails, using them in order to attack distant foes.

Ninjutsu
As the original tailed beast, the Ten-Tails can create a Tailed Beast Ball. In the beast's initial form, the ball is fired as a continuous beam and can overwhelm multiple Tailed Beast Balls from both Gyūki and Kurama without losing momentum; all while damaging six of Kurama's tails and causing a trail of destruction across the landscape. When the Ten-Tails matured into its second form, its Tailed Beast Ball took on a unique, conical shape and gained an immense increase in range, firing speed and destructive power, allowing it to hit targets great distances away from itself, and destroy mountain ranges and entire cities with a single shot. After undergoing several transformations, the Ten-Tails later unhinged and extended its jaw to unfurl a rafflesia-like mouth that functions as a cannon capable of firing massive and extremely powerful Tailed Beast Balls.

With its Rinne Sharingan, the beast can see across extremely vast distances. After amassing its chakra, the Ten-Tails' roar can stir a series of massive natural disasters. To defend its main body, the Ten-Tails can spawn clones of many shapes and sizes, ranging from humanoid to animal-like in appearance, some with weapon-like appendages on their arms. These clones are created directly from the beast's body mass and are extensions of its ability to not only regenerate, but also separate its body, which can be used to purge burning flesh from its main body. As another defensive means, it can quickly form additional arms anywhere on its body to grab enemies who are navigating on it.

Fourth Shinobi World War: Climax
Though only able to obtain fragments of Gyūki and Kurama's chakra, Obito Uchiha begins the Demonic Statue of the Outer Path's regeneration into the Ten-Tails. As Madara Uchiha joins the fray, Naruto and Killer B attempt to wipe out the Demonic Statue with a massive Tailed Beast Ball to stop the Ten-Tails from being fully revived. Though the statue's chakra vanished after the attack, the allied ninja's victory was short lived as the Ten-Tails emerges from the settling smoke. With this, Obito echoed Kakashi's sentiments that it was in fact the end, of this world and not the battle. Elsewhere, though disappointed that he was not able to capture the Eight and Nine-Tails to complete the beast's revival, Madara castes this aside and noted that they needed to get on with the plan.

With the revival complete, Obito and Madara situated themselves atop the beast, from which two tendrils manifested and connected themselves to the two Uchiha. Not wanting to waste any time, Obito noted that he wanted to cast the Infinite Tsukuyomi immediately while Madara wanted to test the beast's power first. As the beast attacked Gyūki and Kurama, it quickly landed a blow on Kurama before the fox had time to retaliate. Landing on either side of the beast, Kurama and Gyūki launched a barrage of simultaneous Tailed Beast Balls at the beast only for the Ten-Tails to counter using one of its own, completely nullifying the oncoming attacks. After the dust cleared, a Naruto shadow clone and Kakashi appeared above the Ten-Tails where Kakashi released Gyūki, who then fired a point-blank range Tailed Beast Ball at the Ten-Tails' eye.

Merely flicking the ball back at Gyūki with a finger, the beast prepares to crush Kakashi and Naruto beneath its tail, but only manages to dispel the shadow clone as Kakashi was pushed to safety. Afterwards, the Uchiha have the Ten-Tails prepare a Tailed Beast Ball to decimate their severely exhausted opponents but much to everyone's shock, it missed. It is revealed that control of the beast had been momentarily wrested from their control. With the battlefield now shrouded in mist and all sensory skills being jammed, the question of whether they thought they were hiding was raised. With a single swipe of its tail, the beast is able to dissolve the mist. Just then the Wind Release: Wind Cutter Technique is used to counter, and when the mist cleared, it is revealed that the rest of the Allied Shinobi Forces had joined the battle.

The Alliance launched a barrage of techniques in order to incapacitate the Ten-Tails, so that they could get to Obito and Madara. As the beast is subsequently immobilised in what was effectively cement, the two Uchiha commented that the effort is futile as the Ten-Tails began its metamorphosis into its mature form. Once fully matured, the Ten-Tails bursts forth from its prison and proceeds to devastate several towns, with the shinobi headquarters and everyone in it targeted as well. After wiping out the headquarters, Madara realises that Ten-Tails is becoming more troublesome to control as he allows Obito to assume command as only he can revive Madara into a living body, allowing him to become the beast's jinchūriki. Once in control, Obito uses the Ten-Tails to channel the Wood Release: Cutting Technique to decimate the Allied Forces with wooden stakes, with Neji Hyūga among the fatally wounded, before it is sandwiched between Kitsuchi's Earth Release: Sandwich Technique. When encouraging words from his friends kept Naruto from breaking, Obito ignoring Madara that he would injure the Ten-Tails wrapped the beast with its tails and prepared to annihilate the Allied Forces with a Tailed Beast Ball at close range. However, before the ball could be fired, Killer B transformed into the Eight-Tails charging his own Tailed Beast Ball, stuffed both into the Ten-Tails' mouth and detonated them, causing the beast to collapse in pain.

After Naruto infused Hinata Hyūga with Kurama's chakra, she was able to deflect one of its tails before Naruto sent his shadow clones to repeat the process with other Alliance shinobi. Overwhelmed by the empowered Allied ninja, the Ten-Tails was restrained by Shikamaru Nara and his Nara clan kinsmen. With Madara's influence, the Ten-Tails was able to resist the Shadow Imitation Technique and attempted to assault the Alliance shinobi with its tails, only to be stopped by their combined efforts. The beast subsequently formed a cage around the Alliance as Obito mocked that it was a fitting fate akin to what the Hyūga subjected its members to. Not deterred by this, the shinobi press forward and cut through their would be bars with Naruto's Rasenshuriken. Naruto was able to force Obito to avoid his Rasenshuriken while Rock Lee attacked Madara, causing the two to lose their means of controlling the beast as they are forced to the ground. However, now acting on its own mindless accord, and maturing even further, the Ten-Tails went on a rampage while completely warping the weather around the area. Obito considered becoming its jinchūriki to contain it, but ended up being caught into battle with Kakashi, going into the other dimension. After the Tenpenchii dissipated, it looked at Naruto and sensed the presence of seven tailed beasts, and saw a mysterious shadow with a pair of Rinnegan. This stirred it and it roared while gathering more chakra, increasing its form once more. It opened its mouth wide, producing a flower-like structure that it used to create a large Tailed Beast Ball, firing it at the Shinobi Alliance. It easily smashed through their Earth Release barriers, but was warped away by Minato Namikaze upon his arrival to the battlefield.

After the reincarnated Hokage had properly positioned themselves, they trapped the Ten-Tails within a large barrier topped with Hashirama's restraints to further immobilise its movements as they prepared to attack the beast. The Ten-Tails, aware that its capture seems imminent, split into miniature clones, charging at Shinobi Alliance. With the help of there respective summons Naruto and Sasuke got past the Ten-Tails' clone army and charged it. Naruto combined his Wind Release: Ultra-Big Ball Rasenshuriken with Sasuke's Blaze Release: Susanoo Kagutsuchi to create Scorch Release: Halo Gale Jet Black Arrow Style Zero which dealt a direct and massive hit on the Ten-Tails. The Ten-Tails then collapsed as the black flames consumed it.

Whilst Naruto and Sasuke were both on opposing views: Naruto intending to remove the tailed beasts inside the Ten-Tails, and Sasuke wanting it to burn until the last cell, as the beast was consumed, the Ten-Tails removed the Amaterasu-consumed area of its body much to the shock of the young Uchiha. When Obito warped out of the other dimension heavily wounded, Madara attempted to force him to revive him, Obito resisted and used that opportunity to make himself the Ten-Tails' jinchūriki, breaking free of the barrier.

Birth of the Ten-Tails' Jinchūriki
Once inside Obito's body, the Ten-Tails made an attempt to consume the human before Obito asserted control over the creature. Ultimately gaining control of the beast, Obito continued to battle the Allied Shinobi Forces where he ultimately summoned the beast from his body and had it assume a recreated tree form for the purpose of casting the Infinite Tsukuyomi. While in this form, the tree begins attacking the shinobi, its roots sapping chakra from its victims. Madara explained the origins of the tree and how it has become the Ten-Tails, and explained that once the lotus flower atop the tree opened, the Ten-Tails' eye would be reflected on the moon and the Eye of the Moon Plan would be completed.

As Obito continued to dominate the battle, waiting for the blooming of the Ten-Tails' tree form to be completed, the senjutsu-enhanced teamwork of Naruto and Sasuke were able to land a critical hit on Obito. This allowed Naruto, Gaara, and Killer B to latch onto the tailed beast chakra within Obito with their own tailed beast chakra. With the combined efforts of the entire Allied Forces, the tailed beasts were freed from Obito, halting the tree's development.

Later, after Madara re-captured the nine tailed beasts and sealed them back within the Demonic Statue, the Ten-Tails revived once again. Shortly thereafter, Madara summoned the beast and ultimately sealed it within himself, making him its newest jinchūriki. When Naruto used the Sage Art: Lava Release Rasenshuriken to cut down the flower of the Ten-Tails' tree form that was left behind by Obito, Kaguya's will told Madara to absorb the falling tree, which Madara believed to be the beast's desire to unite everything into one being.

Kaguya Ōtsutsuki Strikes
Once Madara had completed the Eye of the Moon Plan, he was promptly betrayed by Black Zetsu, who proceeded to use itself and Madara as a medium to absorb enormous reserves of chakra from the victims of the Infinite Tsukuyomi, thereby completing the revival of Kaguya. Soon after, while absorbing chakra from Naruto and Sasuke, Black Zetsu revealed the true story behind the creation of the Ten-Tails and Kaguya's desire to reclaim all chakra for herself. During Team Kakashi's battle with Kaguya, Naruto was able to hit her with nine Rasenshuriken, each containing the chakra of one tailed beast. Resonating with said chakra, the tailed beast chakra within Kaguya's body grew unstable, forming a rabbit-like incarnation of the Ten-Tails which Kaguya was unable to control. However, as she was within her core dimension, Kaguya was able to continue siphoning chakra off the Infinite Tsukuyomi's victims, quickly stabilising the tailed beasts' chakra and returning to her original form. Ultimately, Kaguya was sealed by Naruto and Sasuke. During the process she transformed back into the Ten-Tails and then its skeletal form after the tailed beasts were extracted.

Video Games
Although it is not a selectable character, Obito summons the Ten-Tails in its second form as his awakening in Naruto Shippūden: Ultimate Ninja Storm Revolution.

Trivia

 * Deidarabotchi, also known as, was a yōkai of titanic proportions in Japanese mythology. Kurama's explanation of how powerful the Ten-Tails is reflects Daidarabotchi's role in the formation of Japan's wilderness, such as the two peaks of Mount Tsukuba, according to Japanese myth.
 * The name "Datara" may refer to, a one-eyed, one-legged blacksmith said to live deep in the mountains of Kumano. Myths vary on his nature as a yōkai or the fallen deity Ameno-me-Hitotsu. Either way, the legends say of Ippon-datara's ability to forge living things from metal that makes another reference to the Ten-Tails as the progenitor of the world.
 * The Ten-Tails' Rinne Sharingan has been depicted with varying numbers of tomoe on different occasions. When first shown as a silhouette, its eye contained nine, but it was then depicted with only six tomoe after it revival. During its battle with Hagoromo and Hamura, its eye was depicted with four rows of tomoe, indicating it contained at least twelve. The eye contained in the bud of its tree form has also been depicted with nine and six tomoe on different occasions.
 * In its anime début, the Ten-Tails' eye was first depicted red with nine tomoe during its battle with Hagoromo, but when it was about to be sealed into the moon, its eye was instead purple and lacked tomoe. This mistake was corrected in subsequent appearances.
 * The Ten-Tails can be revived without fully collecting all nine tailed beasts, having a fraction of the chakra of which is enough to revive it in an incomplete form. However, even without the other tailed beasts the Ten-Tails will slowly become its former self, though it takes time for it to "mature" into its complete form, making it harder for Madara and Obito to control it as it does.
 * The mature humanoid form of the Ten-Tails' head has three primary features: an eye, an ear and a mouth. This is possibly a reference to the maxim: "see no evil, hear no evil, speak no evil".
 * The twin rocks Hagoromo and Hamura are seen fighting the Ten-Tails on in Hagoromo's flashback are a reference to the Meoto Iwa, a pair of stones off the coast of Japan that are considered sacred in Shintō. They are bound by and represent the union of the Japanese kami, Izanami and Izanagi. In the real world, the two rocks are located near the Grand Shrine of Ise, the most important location in Shintō.