Yagura Karatachi

was the jinchūriki of the Three-Tails and the of Kirigakure. When the Three-Tails was captured by Akatsuki, it had no host and roamed out in the wild.

Background
During his reign as Mizukage, Yagura was known to have no tolerance for any form of treachery against the village and he reinforced its nickname as by the barbaric ritual where Academy student's would be forced to kill each other in order to graduate. The practice was discontinued when an entire graduating class of students was massacred by a young Zabuza Momochi.

Following the Three-Tails' revival after being "killed", the tailed beast was sealed within Yagura. As a jinchūriki, he became known as the third person to achieve full control over a tailed beast. Around this time, Obito Uchiha took control of Yagura, effectively giving him control over the village. It is likely Obito took control of Yagura through the use of Kotoamatsutsuki and he did so to find out the circumstances of Rin's death, possibly deteriorating the state of Kirigakure as a form of vengeance. The bloodline purge was plausibly instigated by Yagura, under Obito's influence. After Kisame Hoshigaki killed Fuguki Suikazan for leaking intel to other villages, Yagura commended Kisame for killing the traitor, before Obito revealed he was manipulating the Mizukage.

Zabuza Momochi tried to assassinate Yagura during his coup d'etat, but ended up failing and fled the village. Despite his tyrannical reign, many in Kirigakure feared that Yagura was being manipulated, a fear which was confirmed by Ao via the Byakugan he later acquired. Though it was never specified when he died, he appeared to have died shortly before the joint Konoha–Suna Chūnin Exams, as the village was in the process of recovering following his recent passing. The cause of his death is unknown but the Sanbi freely roaming about implied that he might've removed the seal, resulting in his demise.

Personality
Yagura seems to be very formal, outspoken and composed in an almost diplomatic manner as seen when he welcomed Naruto on behalf of all the jinchūriki and tailed beasts. He does, however, have an exuberant and defensive side as seen by his exasperated outburst at Naruto Uzumaki for thinking he was a weak child who had died before experiencing the world as well as ignoring what he was saying. Yagura is also proud of his accomplishment as a Mizukage, claiming to be distinguished in his life, possibly hinting that he had became Mizukage prior to being manipulated by Obito and he had established a good reputation and was respected by the villagers of Kirigakure before it was tarnished. Also, Yagura was very talkative and curious, breaking out of his formality, asking Naruto how it was to kiss Sasuke. Despite his reputation as a ruthless Mizukage, Yagura smiles amicably at Naruto when they first meet, hinting that he might not be as cruel as he was reputed to be though as the duration of his manipulation at Obito's hands is unknown, it is plausible that he never wished to rule Kirigakure that way.

Appearance
Despite his height, and child-like appearance, Yagura was an adult male, with a head of messy, dull olive hair, pink pupiless eyes and what seems to be a stitch-like scar running from under his left eye, all the way down his cheek. He wore a grey, sleeveless shirt with the Kirigakure forehead protector attached to the front, short-sleeved mesh armour over which he also wears a green poncho along with a turquoise sash around his waist, paired with a green apron over his pants. He wears a pair of brown boots, and on his back he carried a staff-like pole weapon with uneven sized hooks with a green flower on the larger end.

Abilities
Yagura was a powerful shinobi, befitting his role as Mizukage. He mastered Isobu's power at a very young age, becoming a perfect jinchūriki. After his reincarnation and serving as one of Tobi's Six Paths of Pain, Yagura is seen with both the Sharingan and Rinnegan. Combining the perceptual and predictive abilities of the former with the shared field of vision ability of the latter, allowed Yagura to use his attacks in a more precise and coordinated fashion as well as react to enemy attacks more efficiently, both individually and in conjunction and with the other jinchūriki.

Nature Transformation
He wielded what resembles a large, hook-ended staff with one end being larger than the other, with a green flower located on the larger end. By incorporating this tool into his Water Release ninjutsu, Yagura was able to create mirrors that can reflect enemy attacks.

Jinchūriki Transformations
As the Three-Tails' jinchūriki, Yagura was granted a significant amount of chakra and stamina from the beast. He was also one of the few people mentioned by Danzō Shimura to have achieved full control over their respective beast. Upon being reincarnated he displayed a partial transformation into the Three-Tails, being able to manifest one of its tails. Furthermore, when attacked and immobilised by B's clone, Yagura transformed into his Version 2 form to escape being sealed. In this form Yagura was able to perform Coral Palm, a technique which causes corals to grow on any surface he chooses, when used on opponents, it restricts their movement and eventually immobilises them. When forced to transform into his full Three-Tails form, Yagura was able to move with both tremendous speed and force by simply curling himself up into a ball. Yagura was also able to use the Tailed Beast Ball in this form.

Fourth Shinobi World War: Confrontation
In preparation for the Fourth Shinobi World War, Yagura was reincarnated by Kabuto Yakushi to fight against the Allied Shinobi Forces, where he was mobilised alongside the other deceased jinchūriki. As dawn broke on the second day of the war, it was revealed that Tobi had turned the reincarnated jinchūriki into his own customised Six Paths of Pain, with each having a Rinnegan and Sharingan in place of their left and right eyes respectively. Each jinchūriki also had their particular tailed beast resealed within them and a chakra receiver embedded into their body.

Fourth Shinobi World War: Climax
Yagura later travelled together with Tobi, in pursuit of Naruto and Killer B. Encountering their targets, the reincarnated jinchūriki were sent into battle. After the enemy evaded Rōshi's attack, Yagura used his Water Release: Water Mirror Technique to counter their attacks; repelling them momentarily. However, when this initial assault failed, he, like the others, unleashes the power of their respective tailed beast by materialising the first of its tails. Incapacitated in the wake of the Eight-Tails' devastating attack, after B's recent transformation, Yagura was then restrained by the latter's sealing technique. However, before the technique's completion, he managed to escape by adopting his Version 2 form, where he then proceeds to strike Naruto from behind and covering him in coral.

Regrouping with the other reincarnated jinchūriki, after Kakashi Hatake and Might Guy's intervention, Yagura charged past the pair towards Naruto. Rallying once again, he along with the other jinchūriki prepare to confront the two Konohagakure jōnin, after Han's previous attack was thwarted by Kakashi. After Son Gokū was resealed into the Demonic Statue of the Outer Path, Yagura was forced to enter his full Three-Tails form, as Tobi prepared to go all-out. Unleashing a Tailed Beast Ball along with the others, the jinchūriki instead resorted to a direct assault when these attacks are deflected by Naruto, only to then be repelled as the latter adopted his Tailed Beast Mode. In the resulting chaos, Yagura evaded the plummeting Seven-Tails by rolling into a ball, before attempting to run over the Nine-Tails. However, he was stopped by the Eight-Tails' grasp, but once freed, the rival beasts regrouped and prepare a collaborative Tailed Beast Ball, launching it towards their opponents only to have it diverted by an opposing one.

As Naruto attempted to remove the opposition's chakra receivers in the ensuing blast, Naruto entered the joint consciousness of the tailed beasts, where Yagura greeted and thanked him for his efforts on behalf of the others. Shocked by Naruto's tearful reaction to his belief that Yagura was a child younger than he was and as such had not experienced the world before dying, he desperately tried to correct Naruto and regain his attention. Once achieved, he introduced himself alongside his tailed beast, Isobu. After Isobu was resealed into the Demonic Statue of the Outer Path, Yagura and the other jinchūriki's corpses were collected by B and held in the Gyūki's tentacles. With the release of the Impure World Reincarnation, Yagura and the others were enveloped in a light of sorts before their bodies start to deconstruct and his soul returned to the afterlife.

Kaguya Ōtsutsuki Strikes
Subsequent to Kaguya Ōtsutsuki being sealed by Naruto Uzumaki and Sasuke Uchiha, he and the other deceased Kage were summoned from the Pure Land by Hagoromo Ōtsutsuki to aid him and the Hokage in summoning Team 7, the tailed beasts and Madara Uchiha from Kaguya's dimension. Later, his and the other Kage's souls were returned to the Pure Land.

Trivia

 * The word means "tower" or "turret". It could also refer to the tombs in the middle ages.
 * In order to prevent the jinchūriki from turning traitor, it is tradition for the host to be selected from the family of the village's own Kage. Due to this, Yagura may have been connected to one of the Mizukage.
 * He bears great resemblance to Yūkimaru, an anime-exclusive character who has the ability to control the Sanbi, hinting at a possible relation between the two.

Quotes

 * (To Kisame) "I can trust you because of who you are, Kisame. For the sake of our nation and village, you've done our dirty work. And additionally, you've followed through on traitorous assignments. You're well aware this world is full of lies, and deceit."
 * (To Naruto) "Welcome! I thank you on behalf of all of us jinchūriki and tailed beasts! I've wanted to meet you, Naruto Uzumaki!"
 * (To Naruto) "I am the former Fourth Mizukage! I was quite distinguished, and an adult!"
 * (To Naruto) "Honestly, just as the Four-Tails said, you don't listen!"