Jūgo

is a shinobi from an unnamed clan, who was being held at Orochimaru's Northern Hideout. He was said to have gone to Orochimaru of his own free will, hoping that Orochimaru would cure him of his rages. He was later recruited as a member of Sasuke Uchiha's group Taka, which was initially called "Hebi" at the time of its creation.

Background
An outcast, Jūgo's rage made him a danger to anyone around him, as they stood little chance of survival should he lose his temper. At one point, he became so angry that he destroyed a village and killed all of its inhabitants. This has caused others to label him as the "Scales", where anything could tip the balance. Cursing his existence, he took to secluding himself in caves, hoping to bring no one any harm. This lasted until he met Kimimaro, who was himself the last remnant of the Kaguya clan. Following Kimimaro, Jūgo allowed himself to be one of Orochimaru's test subjects in the hopes that he could be cured of his fits of rage.

However, amazed by Jūgo's ability to absorb natural energy to undergo various drastic physical alterations at the cost of mental state, Orochimaru's attempts to discover the origin of his clan's ability to use such power led him to the Ryūchi Cave, where he learned to use Senjutsu. Unable to enter Sage Mode, Orochimaru instead devised the cursed seals by combining his Senjutsu chakra and the mutative enzymes he isolated from Jūgo's blood.

As Orochimaru was nearing time to swap vessels, Kimimaro took it upon himself to recover Sasuke Uchiha. Prior to leaving, Jūgo was visited by Kimimaro who explained the situation to him. Despite Jūgo's concerns for Kimimaro's health, he assured him that Sasuke is his legacy while thanking Jūgo for their friendship.

Personality
While Jūgo initially appeared quite bloodthirsty, Karin noted that this was only common behaviour when he was enraged; Jūgo himself didn't want to kill anyone and in reality, he is a very gentle person. His compassionate nature extends to various animals, able to instantly gain their trust. Even more, he dislikes anyone who would hurt animals. His fits of rage are random and uncontrollable, and thus are the reason why he willingly chooses to remain confined where he won't bring harm to anyone. However, he is willing to unleash his psychotic side in battle, as it enhances his fighting capabilities. The only reason he agreed to go with Sasuke is because he views Sasuke as the only person capable of preventing him from killing people while enraged, by the means of killer intent or the Sharingan. He thinks of Sasuke as his "cage". Before Sasuke, it was Kimimaro who kept Jūgo in check, and as Kimimaro was the only person Jūgo came into any contact with, the two grew close. After hearing that Kimimaro sacrificed his life to deliver Sasuke to Orochimaru, Jūgo believes that Kimimaro's spirit continues to live on in Sasuke, and thus is completely loyal to him, even after Taka had been disbanded, and Sasuke left them in the Land of Iron, Jūgo made his way back to Sasuke and matter-of-factly noted when asked, that his place was beside Sasuke as his shield.

Suigetsu couldn't stand Jūgo at first, and commented that one of the reasons he had to retrieve the Kubikiribōchō was because of him. Karin noted that Jūgo is mentally unstable, a view confirmed when Jūgo was muttering to himself over whom he would kill next, which he would determine by gender. While discussing Sasuke Uchiha's team with the other members of Akatsuki, Pain referred to Jūgo as, referencing his dual personality. According to the third databook, he is cowardly in his normal state and violent when natural energy overtakes him. He has also been described as one who "does things at his own pace".

Appearance
Jūgo is a tall, muscular young man who has spiky orange hair, red-orange eyes, and a usually calm disposition. However, when affected by his murderous side, his skin turns dark, his irides become a pale yellow colour while his sclerae turn black, and he grows various weapons and appendages to suit his battle combat situation, as well as having a deranged look. Jūgo has a bracket-shaped symbol on his left palm.

As a child, he wore a yellow shirt with blue shorts. When Jūgo was first introduced, he wore a pale blue shirt and pale green shorts. Later when Tamaki tried to find him some clothes, he wore black pants, a purple curtain he wore as a cape (Tamaki not able to find a shirt big enough for him), and brown sandals. After Taka had allied with Akatsuki, Jūgo was shown wearing an Akatsuki robe.

Years later while working for Orochimaru, he developed a stronger jawline and dons his hair in an up-do while keeping the sides short. Attire-wise he wears a ragged, dark-coloured cloak.

Abilities
Jūgo's abilities undoubtedly make him a dangerous individual, enough to gain the interest of other powerful ninja such as Orochimaru and Sasuke Uchiha at separate times. After adapting their DNA and abilities, Kabuto also indirectly praised Jūgo when noting the quality of Sasuke's former team. A special trait of Jūgo's, is his ability to understand and communicate with animals, such as birds, who can be sent to travel far distances to scout and gather information, and quickly report back. Jūgo can also transfer his chakra onto others, as seen when he infused Sasuke's Susanoo with senjutsu chakra, and in the anime absorb chakra through physical contact and heal most injuries instantly. Jūgo's nature transformations include Earth, Water, Wind, and Yang Release.

Sage Transformation
Like other members of his clan, Jūgo possesses the ability known as Sage Transformation, which allows him to use the natural energy he absorbs to transform his body at will. He can change what form he takes almost instantly and can isolate the transformation to specific parts of his body. Also due to this, Jūgo's possesses massive reserves of powerful chakra. However, because he absorbs natural energy constantly, he and his clansmen are prey to sporadic and involuntary surges of rage.

As a result, Jūgo has changed his body into a number of forms. At his début, he changed his left arm into a piston-like ram to increase his punching power and then altered it into a massive axe blade to counter Suigetsu's sword. While Taka was fighting Killer B, Jūgo formed a set of arm-boosters to both throw his team-mates a large distance and to produce stronger punches. He also created another set of boosters on his back to increase his speed in order to avoid a Lightning Release: Lariat at the last second from a Version 1 Killer B. Jūgo is also capable of extending his arms to great lengths to catch targets several feet away from him. Aside from his shape-shifting powers, Jūgo's physical abilities, such as his speed, strength, endurance, resiliency, and durability are also enhanced in proportion to the level of the transformation and intake of natural energy. His transformations grew stronger following the years after the war.

If he fully transforms, Jūgo gains a massive boost in overall ability but loses his mind to his murderous side, signified by a change in his voice. When transforming, Jūgo's skin turns dark and his sclera turn black. He also gains a black stripe running from the middle of his forehead and down the bridge of his nose. In this full form, Jūgo is incredibly resilient and has significant reflexes, being able to react to and take a punch from the lightning-enhanced Fourth Raikage that penetrated both his arm and chest, yet still managing to retaliate almost immediately after with ease, despite the speed and power of the attack and injury he had sustained. In this form, he turned his arm into a shield to defend himself and created Multiple Lotus Nonself Connected Cannons on his back that were capable of devastating the area.

Jūgo's clan abilities serve as the origin of Orochimaru's Juinjutsu that he brands his various followers with, which were created using Jūgo's own bodily fluids that were then injected into the intended individual. As such, he is able to use its power to its full extent without it eroding his body. Unlike those who have been given a cursed seal, Jūgo is not limited to one transformation, and can enter whatever form is best for the situation. Jūgo considers those who have received one of Orochimaru's cursed seals to be one of his "copies" and, since they have proven compatible with his own DNA, he is able to give them some of his flesh to heal their injuries. However, this has the side effect of shrinking him and giving him an overall younger appearance. He can similarly consume others to heal his own injuries and return to his original 'adult' form, though they do not need to be cursed seal recipients. In the anime, Jūgo can similarly consume cursed seals from wildlife, effectively curing it, though taking them into himself strains his ability to contain his violent impulses.

Itachi Pursuit Mission
After defeating Orochimaru, and recruiting Suigetsu and Karin, Sasuke travelled to Orochimaru's Northern Hideout, to recruit Jūgo. Initially unwilling to join forces with Sasuke, Jūgo tapped into his ability, but was then frightened to release it after sensing Sasuke's killer intent. He then joined the newly formed Hebi in their mission to hunt down and kill Akatsuki's Itachi Uchiha, Sasuke's older brother.

Fated Battle Between Brothers
Jūgo would later discover multiple hidden bases belonging to the Akatsuki, where Sasuke confronted a clone of Itachi in one of them, who challenged Sasuke to meet him at the Uchiha Hideout. Jūgo remained behind with the other members of Hebi and Kisame Hoshigaki as Sasuke confronted Itachi.

Pain's Assault
After Itachi's death, and Sasuke's "education" in his brother's true past by Tobi, Jūgo and the other members of Hebi were reformed into Taka. Having allied themselves with the Akatsuki, Taka was sent to capture the Eight-Tails, so that it could be extracted from its host, Killer B. Infiltrating Kumogakure, they confronted Killer B, only to have him defeat Suigetsu. When Jūgo attempted to defeat him as well, Killer B overpowered him using the sword he stole from Suigetsu.

After Sasuke was critically injured, Jūgo tells Karin that she did not have enough chakra to heal him and starts to infuse some of his flesh with Sasuke's, to heal his wounds, saying it would work as Sasuke was compatible with the cursed seal (and hence Jūgo's own DNA). This however somehow reduced him to a younger appearance. When their team started working together, Jūgo concentrated on removing his team-mates from danger, even though he initially objected to rescuing Karin, as he thought she would die from Sasuke's Amaterasu. Sasuke was eventually able to capture Killer B, albeit a fake, and Jūgo recuperated with the rest of Taka. As Taka rested in one of Akatsuki's hideouts, Karin sensed J|a spy had followed them. Jūgo and Sasuke went and intercepted him, and left the hideout for a new one shortly after.

Five Kage Summit
Taka later set out for Konoha. On their way they were intercepted by Tobi who informed them that Konoha had already been destroyed. Zetsu, who suddenly appeared, then explained that a man named Danzō had been named Hokage. As per Tobi's advice and orders, Sasuke changes their goal to the Kage Summit. Taka is then guided by Zetsu, who had split up into two bodies.

Jūgo and the rest of Taka arrived at the Land of Iron, and after Suigetsu scouted the area and reported there are many guards, Sasuke tells Jūgo to use animals to find the least guarded route. Their presence is soon discovered and Sasuke engages the samurai that come after them. When Karin becomes preoccupied with worrying about Sasuke, Jūgo tells her to continue looking for Danzō while he goes to help Sasuke.

Taka is attacked by Kumo-nin that Jūgo identifies as two jōnin and the Fourth Raikage. Knowing their presence will make it difficult for Karin to locate Danzō without exposing herself, Jūgo resolves to kill them. He fully transforms into his cursed seal level 2 and goes into his murderous mental state. The Raikage quickly overwhelms him and forces him into a wall, punching through a defensive shield on his arm and into his chest. Though he has seemingly been killed, Jūgo smirks and aims Multiple Lotus Nonself Connected Cannons from his back straight at the Raikage, firing them at point-blank range. Believing the Raikage to be dead, Jūgo prepares to attack someone else, but he is then hit again by the Raikage with a sudden elbow strike. Jūgo smashes against the wall and seems to be knocked unconscious.

As the battle unfolds, Sasuke destroys the room they are in, and Jūgo, having regained consciousness is buried in the rubble. He absorbs the body of a nearby samurai, healing his wounds and returning him to an adult state. He is later seen with Suigetsu, who suggests that they follow the Raikage and Sasuke. Jūgo tells him not to do so because they would be killed. However, Suigetsu says that he has a plan in mind. They try dressing up as samurai to flee the area but are quickly discovered and imprisoned by the samurai.

Fourth Shinobi World War: Confrontation
As the war was being waged, Suigetsu and Jūgo escape their cell in the Land of Iron, having taken care of the guards, and stating that security had gotten looser. Jūgo thinks they should look for Sasuke, but settles for helping Suigetsu find his sword. They also decide they should look for Karin. When they are unable to find Suigetsu's sword, Jūgo asks Suigetsu why he is so serious about it. Suigetsu tells him a bit about the Seven Ninja Swordsmen of the Mist, telling him about its swords and those who wielded them in the past. Jūgo learns that it's Suigetsu's dream to reform the Swordsmen, and to become their leader. Suigetsu also states that he is nicer than Karin.

Fourth Shinobi World War: Climax
Jūgo and Suigetsu escape from the samurai compound. They walk through a forest and discuss their plans. As Jūgo wonders if Karin and Sasuke were all right, Suigetsu tells him that even if they reunited with Sasuke and Karin, it wouldn't be a grand reunion of sorts as Karin wanted Sasuke to herself in order to seduce him. As they continue onwards, Jūgo asks if they would continue looking for swords or find Sasuke and Karin, Suigetsu tells him that they'd continue to get in Karin's way which was his second favourite thing to do after collecting swords. They proceed to head towards one of Orochimaru's hideouts. After receiving intelligence from the birds about the war that was currently going on, Jūgo questions Suigetsu's motives for staying with Taka. During their conversation, Jūgo loses control of himself and violently attacks Suigetsu sending the upper half of his watery body crashing into a wall. This reveals Orochimaru's secret room and with it, information that Suigetsu claims will be beneficial to them.

Later, when Sasuke was being tormented by thoughts concerning what he was, Jūgo and Suigetsu break through the ceiling and enter. Suigetsu examines Kabuto's body while Jūgo examines Anko, the latter stating that she is alive. When Sasuke asks them their purpose of coming there, Suigetsu hands him the scroll — the one with which he exclaims that their group Taka can rule the world with — and making him cognisant of reincarnated Madara's presence even though Itachi forced Kabuto to release Summoning: Impure World Reincarnation, which leaves Sasuke somewhat surprised. Jūgo later helped Sasuke in reviving Orochimaru by giving Sasuke a portion of Kabuto's modified reptilian flesh. Despite Suigetsu's vehement opposition to this, Jūgo simply noted that he would carry out Sasuke's will — a will he believed by extension was that of Kimimaro.

With Orochimaru revived, the team headed towards Konohagakure with the Sannin, where they sensed Naruto Uzumaki's chakra leagues away but pressed on nonetheless at Sasuke's behest. Heading silently towards a dilapidated temple, and then back through Konoha, Jūgo used the natural energy from his Sage Transformation on Orochimaru's cue, to activate the spores that were attached to Sasuke, shrinking in the process. Moving to subdue one of the spare clones, Jūgo absorbed the clone regaining his normal size. With this, he looked on as the four previous Hokage that are reincarnated before him. Listening on silently throughout the proceedings, Jūgo is shocked when Tobirama unleashed a swell of killing intent when he heard Sasuke's intentions to exact revenge on Konoha. Moving almost instinctively, Jūgo moved in front of Sasuke until the situation was quelled by Hashirama. When Sasuke decides to aid the Allied Shinobi Forces after hearing Hashirama's story, Jūgo accompanies Sasuke to the area of the battlefield where Sasuke's former team-mates are.

Birth of the Ten-Tails' Jinchūriki
With the situation looking grim as the Alliance was trapped in a barrier with a Tailed Beast Ball-firing tree, Jūgo made his way back over to Sasuke and noted that they needed to get away, and called for Sasuke to use his Summoning Technique to escape. They are, however, stopped by Naruto who demands they stand before him so he could give them his chakra. Jūgo later found himself safe and outside the barrier where he questioned what Naruto had done and listened on as it was explained how Naruto and Minato's actions had saved them. Jūgo subsequently watched on as the tree form of the Ten-Tails attacked and killed the shinobi around them. As Sasuke then began his next attack against Obito, now knowing that the jinchūriki was vulnerable against senjutsu, Jūgo transferred some of his natural energy into Sasuke, who then proceeded to channel it into his complete Susanoo in a manner similar to the Cursed Seal of Heaven. The combined effort of the Alliance is ultimately enough to defeat Obito. However, they are soon faced with the threat of a revived Madara and Tobi who assaulted them with a giant wooden statue.

Though initially shocked when a distraught Karin lead the charge against the new threat, Jūgo joined the fray and was able to catch Karin after she is attacked and removed the stakes from her body as she recovered. As the later raced towards where Sasuke was, Jūgo considered the situation and the fact that Orochimaru might try to take Sasuke's body, apparently ignorant of the fact Orochimaru can only use the Living Corpse Reincarnation once every three years, along the way, Karin detects a new sinister chakra near Sasuke. Upon arriving, they discovered the new chakra signature was from Kabuto, who had escaped the loop of Itachi's Izanami. Kabuto plainly stated that he no longer desired Sasuke and, in fact, was attempting to heal him. When Orochimaru asked his former assistant why he was doing this, Kabuto explained that his experience under Izanami's power restored his clarity on who he really was, and now merely wished to return to the Konohagakure orphanage he grew up in and correct his mistakes. Eventually, Kabuto succeeded in healing Sasuke, who quickly returned to his feet and was ready to resume the battle. Jūgo and the others were later caught in the Infinite Tsukuyomi when Madara cast it.

Kaguya Ōtsutsuki Strikes
Ultimately, he and the rest of the world were freed from the genjutsu by Naruto and Sasuke after they ended the war.

Blank Period
After the Fourth Shinobi World War ended, Jūgo, Suigetsu and Karin returned to Orochimaru as his subordinates, with Karin being reassigned to a different hideout.

Sasuke Shinden: Book of Sunrise
Jūgo seems surprised and delighted to see Sasuke for the first time in years since the war ended. Sasuke arrives at Orochimaru's hideout to gather information on the Dark Thunder Group and doesn't stay long to greet Jūgo. As they talk with Karin, Jūgo and Suigetsu wonder why Sasuke is reluctant to permanently settle down in Konoha. Karin replies that Sasuke's possession of the Sharingan and Rinnegan earn him enemies and he is avoiding the village in order to protect it.

Sarada Uchiha Arc
Fifteen years after the Fourth Shinobi World War ended, when Sasuke, Naruto Uzumaki, Sarada Uchiha and Chōchō Akimichi came to learn about Shin Uchiha, they were greeted by Jūgo and Suigetsu. The group then followed Orochimaru into the depths of the hideout to discuss the situation. Later, Jūgo joined Orochimaru in aiding Sasuke to find Shin. Sasuke then activated his Rinnegan and prepared to go in his Susanoo.

Jūgo Arc
In the anime, sometime later Jūgo went to a village on the outskirts of the Land of Fire. His Sage Transformation randomly activated again, causing him to go berserk. He was later found by Boruto Uzumaki. While attempting to kill the genin, he was knocked off the cliff by Nue and fell into a river. He was later found by the villagers and taken to their village. When he awoke, back to normal, he was approached by Boruto, along with Sarada and Mitsuki. When asked what he was doing there, he remained silent. The questioning was cut short when one of the villagers, who mysteriously obtained a Cursed Seal, began attacking the villagers. He was drawn to Jūgo, who quickly subdued him. As he began feeling his Sage Transformation kick in, he told the genin to stay away from the forest before retreating to an underground location. He was soon approached by Boruto and Sarada, where Jūgo fully transformed and went berserk.

Jūgo was countered by Konohamaru Sarutobi, but Jūgo was able to both injure him and drain him of a lot of chakra. Konohamaru managed to snap him out of his blood-lust with a Rasengan. Jūgo left, and was followed by the team, who found him passed out with an injection device near him. Tosaka examined and took his blood. After he woke up, Jūgo made the cursed seal in one of the birds recede, and made his dislike of Boruto over his previous bird kill known. Team 7 later observed him curing more bird, and then retreating to his cave when the strain caused him to have another episode. He insisted Team 7 should leave, but relented after seeing they wouldn't, and explained how to he determined which birds were infected even before they become violent. Boruto concealed Jūgo's involvement when a group of Land of Rivers researchers asked them about the information on the birds, and later administered a tranquilliser dose when Jūgo started having another episode, earning his trust. He later discussed the lack of progress in their investigation with the team and Tosaka, while being spied on by one of the Land of Rivers researchers.

Over the next couple of days, Jūgo continued curing birds and tagging them. Sarada reminded Jūgo to take his medication, which she had convinced him to take regularly instead of only when he felt a transformation coming. He commented it helped, but dulled his senses and made curing the birds harder. When Boruto found a domesticated goose among the wild ones, Jūgo determined it wasn't infected. He compared the goose's inability to fly with his own restricted freedom due to his cursed seal and expressed concern with the wild geese migrating and spreading the infection. At the end of the day, Jūgo went back to his cave as a precaution, his body had begun to develop an immunity to the medication. On the third day, Jūgo struggled to contain a transformation, and the group discovered his remaining shots had vanished. Jūgo rampaged at the village, but the Land of Rivers researchers subdued him with tranquillisers and bound him in chains.

When he awoke, Jūgo found himself restrained inside a research base where Tosaka explained the situation. Later, Jūgo was approached by Suigetsu and Boruto. Before they could free him, Tosaka subdued them with tranquilliser, revealing himself to be in league with the researchers and their cursed seal operation. Tosaka went on to explain he started the cursed seal outbreak to lure Jūgo out, wanting to use him as a research subject in the development of his cursed seal weapon. He injected Jūgo with a drug to trigger his transformation, wanting to test his weapon against the original cursed seal's power, even killing his own subordinates when they attempted to kill Jūgo to avoid his transformation. As the transformation proceeded and he broke free, Jūgo begged Boruto to flee.

Jūgo fought to contain his transformation as he arrived at the lake. Tosaka arrived and fully transformed with his cursed seal to defeat and restrain Boruto before he turned to Jūgo. When Jūgo fully transformed, he quickly defeated Tosaka and proceeded to absorb his cursed seal. Still on a rampage, Jūgo turned his attention to Boruto until Nue intervened. Nue kept Jūgo occupied long enough for Boruto to devise a plan on how to revert Jūgo's transformation by inflicting significant damage. Boruto used Jūgo's own increased speed to augment the damage of his Rasengan, causing the transformation to recede at the last moment. Mitsuki arrived with Konohamaru and Suigetsu, having acquired a serum to cure the birds, which Suigetsu ingested and merged with the lake to rain over them. Jūgo left with Karin and Suigetsu, who had also taken a powerless Tosaka with them for their trouble. He watched as a domesticated goose flew by and wondered if he would be able to fly as well one day.

Trivia

 * The name "Jūgo" is made up of the kanji for and, possibly referring to his size and temperament. Interestingly, the first kanji can also be used as a suffix meaning "-fold/-ply", referring to his multiple personalities.
 * Studio Pierrot's Settei sheets of Jūgo show that he was 174cm around the time Kimimaro died.
 * Jūgo's birth date, October 1, makes his Western astrological sign Libra, or the scales.
 * According to the databook(s):
 * Jūgo's hobbies are forest bathing and playing with birds.
 * Jūgo's favourite foods are small fish and beef and he dislikes chicken.
 * Jūgo himself doesn't want to fight. However, when affected by his murderous side, he would fight anyone.
 * Jūgo's favourite phrase is.
 * Jūgo has not completed any official missions.
 * Despite Jūgo being a user of Sage Transformation, none of his techniques are listed as senjutsu in the fourth databook.

Quotes

 * (To Sasuke) "I can't let you die… You're all I have left to remember Kimimaro."
 * (To Suigetsu) "Sasuke's will is Kimimaro's will. And I obey it."