Ten-Tails

The is a primordial entity and the known origin of all chakra. It's more commonly referred to as the, a beast created by the combined entities of the Shinju and Kaguya Ōtsutsuki to reclaim the chakra inherited by her two sons, 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 Akatsuki. The world of ninja united in opposition of this goal, 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. Angered at the power gained by her children, Kaguya fused with the Shinju into an entity that would be christened by many as the "Ten-Tails", which ravaged the world attempting to reclaim 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 that humanity now possesses, 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 Shinju is an impartial entity and was completely devoid of feelings or even ideals as it stayed neutral and almost ambivalent to the constant wars that were waged around it by mankind. As the Ten-Tails, it 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. Kaguya's will becomes more apparent when she told Madara (having mistaken it for the Shinju's) to absorb the tree.

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 red-coloured Rinnegan 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.

In its original form, the Shinju is a gargantuan tree. When it was recreated by Obito, it appeared as a tall, straight trunk, on top of which was a flower bud containing the Ten-Tails' eye.

When Kaguya Ōtsutsuki lost control over the tailed beasts inside her after being hit by Naruto's attack, she turned into the Ten-Tails that manifested as a bloated, rabbit-like form which she had no control over.

Abilities
As the original form of all nine tailed beasts, the Ten-Tails was said to possess massive and overwhelmingly foul chakra that is potent enough to bring total despair and destruction to the world. Not only is the Ten-Tails the source of all chakra, but also the progenitor of everything that exists in the world. It is a god that created countries and has the power to swallow oceans, split the land, and carry mountains. In addition, Kurama admitted that it alone wouldn't even stand a chance against the Ten-Tails, and stated that the Sage told them that its revival would result in the end of the world. When Naruto Uzumaki attempted to use Sage Mode to gauge the power of the beast, he was overwhelmed by the vastness of the beast's power, which Kurama noted as immeasurable. Its power was reaffirmed when the beast's chakra completely warped the shape of the Sensing Water Ball at the Allied Shinobi Forces' Headquarters into two connected spheres. It has been stated by Gyūki that if the Ten-Tails was allowed to reach its final form, then there would be no chance of defeating it.

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 is able to overwhelm multiple Tailed Beast Balls from both Gyūki and Kurama without losing momentum; all while still 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 as well as destroy mountain ranges and entire cities with a single shot. After gathering a considerable amount of chakra and 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.

Even in an incomplete state, the Ten-Tails possesses immense physical strength and is remarkably fast, despite its tremendous size, as it was able to attack both Naruto and Killer B before either of them could react. It casually flicked back a Tailed Beast Ball with one of its fingers, and could cause a massive-scale earthquakes, 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. Obito noted that it could even withstand the backlash of its own Tailed Beast Ball fired at point-blank range, though Madara believed that the beast would still be wounded. Obito's assumption was proven correct when the Ten-Tails' Tailed Beast Ball, 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 cause it irritation without doing any lasting damage, despite Amaterasu on its own being able to neutralise Gyūki.

With its Rinnegan, the beast is able to see across extremely vast distances. A single swipe of its tail 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. After further 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.

In its original form, the Shinju's roots are capable of extending and capturing enemies as large as tailed beasts, allowing it to absorb their chakra to the point of desimating them almost instantly. When the Shinju's 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 Shinju's roots are gradually reduced to shells of their former selves, ultimately becoming White Zetsu.

In its first form, Madara and Obito were able to 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 was able to use 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.

Ten-Tails Revival Arc
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 was preparing to launch a point-blank range Tailed Beast Ball.

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. 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 extracted the beast from his body and had it assume its true form: the Shinju. 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 Shinju's 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 Shinju 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.

Infinite Tsukuyomi Arc
Later, after re-capturing the nine beasts and sealing them back within the Demonic Statue of the Outer Path, the Ten-Tails revives once again. Shortly thereafter, Madara Uchiha summons the beast and ultimately seals it inside of him, making him its newest jinchūriki. When Naruto used the Sage Art: Lava Release Rasenshuriken to cut down the Shinju's flower form that was left behind by Obito, the beast within Madara told him to absorb the falling tree, to which Madara noted to be the beast's desire to unite everything into one being.

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 revive 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, the woman suffered an injury, severing her arm shortly before being hit by Naruto's tailed beast powered Rasenshuriken. Reacting to the the tailed beasts chakra in Naruto, the Ten-Tails' chakra left Kaguya's body as a giant mass of chakra made up of the tailed beasts and one rabbit-like head. Black Zetsu noted that this inhuman form of the Ten-Tails is beyond Kaguya's control making it unstable.

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

 * literally means 'god tree', and its size and nature have connections to both the world tree and the tree of life, motifs that are present in several real-life religions and mythologies throughout the world.
 * In addition, the story of the Shinju bearing the forbidden fruit is very similar to the story of the Tree of the knowledge of good and evil in Abrahamic religions, where Adam and Eve, the first humans, ate the forbidden fruit despite being told otherwise. Ultimately, while becoming wiser, it lead to their downfall by incurring the wrath of God. For disobeying Him, He forever cursed the two and their descendants. Adam's eldest son, Cain, would murder his younger brother, Abel, in anger and jealousy following God's rejection of his offering while accepting Abel's, which alludes to the struggle between the two sons of the Sage of the Six Paths.
 * The wooden dragon-like entities at the base of the Shinju may be a reference to Nidhogg, a dragon or serpent who eternally chews the roots of Yggdrasil in Norse mythology. Likewise with the appearance of the Shinju, it is said that should Nidhogg finally be free of its entrapment underneath Yggdrasil, its appearance into the world beyond its roots are said to herald the coming of Ragnarok, the end of the world and ultimate battle of the gods.
 * 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' eye has been depicted with varying numbers of tomoe on different occasions. When first shown as a silhouette, and after being transformed into the Shinju by Obito, its eye contained nine tomoe. After its revival, and on the genjutsu mural Madara used to tell Obito about the beast, its eye contained only six tomoe. During its battle with Hagoromo and Hamura, its eye was depicted with at least twelve tomoe.
 * 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. In addition, after having the tailed beasts extracted from it, its original form still remained on the battlefield afterwards, even though the Demonic Statue of the Outer Path still existed within Obito's body, and was later extracted from him by Madara.
 * 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", alluding to the fact that the beast is not inherently malevolent, but is actually being used for nefarious purposes by Kaguya, Madara and Obito.
 * 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.