Kabuto Yakushi

is one of the main antagonists of the series, who was first introduced as a Konohagakure genin. He was later revealed as Orochimaru's personal medic, assistant, and general right-hand man. After Orochimaru's sealing, he joined forces with Tobi during the Fourth Shinobi World War.

Background
Kabuto's earliest childhood memory is being found by a young nun on the outskirts of a destroyed village. Suffering from a head wound and amnesia, he had no recollection of his parents or his own identity. The nun treated his wounds with medical ninjutsu and brought him to an orphanage. Shy and reserved, Kabuto did not speak to anyone or thank the nun for her kindness, which led a fellow orphan, Urushi, to question whether or not he had any manners, before slamming a helmet on Kabuto's head to protect his healing wound. When Urushi declared that his lack of a name was annoying, the nun decided to name him "Kabuto", after the helmet. Later that night, Kabuto felt guilty about not thanking the nun and got out of bed to find her, only to get in trouble with the other wards for being up past his curfew. When they took him to a clock to teach him the curfew time, it at first seemed that he was too young to tell time, but the nun recognised that he was squinting and lent him her glasses, allowing him to impress the other caretakers by correctly determining the time of the curfew despite his young age. Because the orphanage could not afford glasses for him, the woman let him keep hers, and Kabuto broke down in tears, repeatedly thanking her as she comforted him.

At some point in time after this, Kabuto was found amongst the dead enemies after the Battle of Kikyō Pass by a captain of the Konoha Medic Corps. The captain brought Kabuto to Konoha and raised him as a son. Using the fact that Kabuto's origins were unknown, Konoha decided to raise him as a spy and was taught Medical Ninjutsu so that the enemy would easily trust him. As a spy for Konoha, he travelled to many countries. Eventually, when Kabuto lost track of his own true self due to not knowing where he came from and the constant changing of his identity to fulfil his role, the village ceased trusting him and he was removed from missions altogether.

Later in life, Kabuto was recruited by Sasori of Akatsuki, who sent Kabuto to spy on Orochimaru by using Memory-Concealing Manipulative Sand Technique to transform him into a sleeper agent. Orochimaru discovered this, and released Sasori's control over Kabuto's memories, leaving Kabuto with the option to follow him. With a little persuasion, Kabuto agreed to side with Orochimaru.

Kabuto has since used his expertise in spying for Orochimaru, playing the role of Sasori's servant to gain knowledge of Akatsuki's plans. Through his affiliation with Konoha, Kabuto was also able to acquire the rank of genin and enter the biannual Chūnin Exams, using the first two parts of the exam to gather information on his fellow participants for Orochimaru's use. Additionally, with the medical expertise taught to him by his adoptive parent and his high intelligence, Kabuto is able to carry out human experiments alongside Orochimaru, while at the same time increasing his own knowledge of the human body.

Personality and Loyalty
Kabuto's loyalties and personality are difficult to discern, as he is a sadistic, yet polite, helpful man with a dry sense of humour. He enjoys playing mind games with his enemies, often unnerving them by pointing out their weaknesses and turning personal horrors against them. During the Fourth Shinobi World War, he freely resurrected people not only for combat, but also to mentally attack his opponents, and saw the personalities of those he brought back as nothing but pawns. Despite this, he seems to have a hard time tolerating rudeness, indicated by his frequent admonishments of Sasuke Uchiha for not treating Orochimaru with respect. Orochimaru also seems to have a hard time determining Kabuto's thoughts at times, as seen when he orders Kabuto to kidnap Sasuke, and wonders if perhaps Kabuto will kill him instead, even giving hints that now would be an opportune time to halt his plans. Even in this instance, Orochimaru has great confidence in Kabuto's loyalty, often laughing at the prospect that Kabuto would betray him.

While Kabuto does generally obey Orochimaru's orders, even going so far as to save Orochimaru's life at times, he is not above helping Orochimaru's enemies; for example, he heals Sakura Haruno and Hinata Hyūga on different occasions. When healing Sakura, Kabuto hints at an ulterior motive, saying that Akatsuki is the true enemy; Orochimaru later says something similar, pointing out that the death of more Akatsuki members means fewer enemies for him. He is also generally polite to Naruto Uzumaki, upon whom Kabuto possesses a peculiar fixation on, despite the fact that they have conflicting motives during their encounters. Despite his unclear goals, Kabuto seemed to be content in following Orochimaru, using the alignment to make requests for specific bodies with which to further his knowledge.

Kabuto shows a clear view of respect to those he sees with great status, as he told Tsunade that he had the utmost respect for her as a fellow medical ninja. He sees the Sannin as great and powerful ninja, and even takes much excitement in testing his mettle against them. Due to this trait, he sees others who have not gained a high and famous reputation as nothing but inferior fighters with no skill in combat and ability.

Kabuto stated that he dislikes forcing people to do things against their will, and instead he would manipulate them by acting sympathetic to them. He plotted to send an ill Kimimaro to retrieve Sasuke, but merely spoke about how much Orochimaru is suffering, in order to stimulate Kimimaro's loyalty to move against his ill body. Orochimaru noted that Kabuto has a nasty personality. Kabuto also claimed that he is an introvert, and prefers secluded places. Due to this, he considers the Impure World Resurrection technique will bring him unwanted infamy and attention, which he notes to be the so-called perfect technique's downside.

Since merging the remains of Orochimaru into his body, Kabuto has shown to have the ambition to surpass Orochimaru. He has also recently shown interest in furthering his knowledge of techniques, the goal of his former master and as such, apparently wants to acquire Sasuke for this. He also showed interest in experimenting on Yamato and Zetsu. One of his goals seems to be able to learn the secrets of the Sage of Six Paths. Whether or not this personality change is brought on by Orochimaru's remains or not remains to be seen.

Also, while pledging an allegiance with Tobi and Akatsuki, as well as offering to resurrect an army of powerful men, Kabuto had previously provided Naruto a book containing all the information on Akatsuki, as well as leaving a trail of corpses to allow Anko Mitarashi and her brigade to follow into Mountains' Graveyard. This was apparently to lure Anko into a trap so he could capture her in order to extract her chakra, and he refused to kill her on Tobi's orders. Tobi also suspects that Kabuto plans to use the war to weaken both the Allied Forces and his own fighting power after learning that Kabuto had led the Konoha ninja to his hideout.

Kabuto, despite his rather cool personality at the beginning of the series, has been shown to be inwardly conflicted with major insecurities. According to himself, until Orochimaru was sealed he was rather unsure of his identity. He stated himself that he would now do what he wanted to do as he felt no loyalty to even the people or village that raised him, detesting the fact that he had been brought up by the enemy of his people. He claimed to not know who he really was or what he wanted to do until thinking about how Naruto achieved his resolve. Overall, Kabuto likens himself with Itachi Uchiha, both of whom served Konoha in the dark but were shunned by the village in return, and claims that because of this, he understands Sasuke more than anyone.

Appearance
Kabuto's trademark is a pair of circular glasses, a gift from the nun who rescued and took him in, and he is rarely seen without them. He has black eyes and grey hair, which is normally kept in a ponytail. In the majority of his earlier appearances he wore a dark purple shirt with a high collar, a white undershirt, fingerless gloves with armored plates on the back of the hand, a white cloth waistband worn at an angle, dark purple pants, blue sandals, and a shuriken holster on his right leg. He typically wore an Otogakure forehead protector, but was first seen wearing a Konohagakure forehead protector as part of his genin disguise. Kabuto was also known to disguise himself as a member of Konohagakure's ANBU, and occasionally cloaked himself in a hooded mantle.

Shortly after Sasuke counter-absorbed Orochimaru, Kabuto took cells and tissue from the remains of Orochimaru's true form and implanted them in his body. The cells and tissue slowly began to take over his body, but he resisted their influence and eventually learned to fully control Orochimaru's genetic material, causing him to take on many physical traits of his former master. These include Orochimaru's purple eye markings and serpentine pupils, as well as scaley patterns on his face and much of his body. He no longer wears his hair in a ponytail, instead leaving it unkempt and allowing it to grow out. He wears a wine-colored cloak with a hood designed to resemble a serpent's head, with white, red, and yellow markings that resemble eyes; the hood can be closed like a snake's mouth to help protect his senses from the effects of genjutsu. He also appears to have a long, white snake fused with his abdomen, which is kept wrapped around his waist and often seen slithering out from under his robes like a tail. He can shed his human body, taking on the appearance of a monstrous snake with sharply distorted facial features and arms.

Abilities
Despite officially being a genin, Kabuto has proven himself to be a skilled and cunning ninja far beyond that level, particularly because of his medical abilities. His skills are said to rival those of Kakashi Hatake on more than one occasion. He has been shown to be able to kill ANBU members with relative ease and even mockingly stated he could handle at least ten ANBU members. Through keen observation, Kabuto can quickly determine the situation at hand. Even when up against a stronger opponent, he can take advantage by quickly exploiting their weakness. Kabuto is also very adaptable, as when Tsunade flipped his nervous system signals, he managed to regain control of his body quickly, a feat that impressed Tsunade.

Kabuto's chakra reserves have increased tremendously after he integrated and controlled Orochimaru's remains. A testament to this is his ability to summon and control dozens of resurrected ninja at one time for up to two days, and summon Manda II, a snake even larger than Manda. After having captured Anko, he becomes even more powerful just by absorbing Orochimaru's residual chakra that resides in her. His reserves are large enough that he is able to enter Sage Mode.

He is capable of using Earth Release to move underground. Though he has made little use of it since his introduction, Kabuto is also a skilled genjutsu user, having once put almost an entire stadium to sleep during the Chūnin Exams. In the anime, he also showed the ability to make himself invisible. Kabuto has also displayed some skill with barrier ninjutsu having erected one around his proximity during the Fourth Shinobi World War in order to hide his location.

Taijutsu
While claiming to have lesser skill in taijutsu, Kabuto has shown proficient enough to hold his own against Tsunade, a skilled taijutsu fighter known for her devastating strikes, after tiring her out and consuming a Military Rations Pill. His main style of taijutsu is to use the chakra scalpel, which allows him to form his chakra into a blade and hit his target's muscles, pressure points, and other key points of their body. During his battle with Tsunade, she remarks that Kabuto's senses and sharpness may have surpassed hers in her prime. First, he will quickly assess his opponent's strength and battle style to comprehend their movements, thereby allowing him to easily predict and dodge their attacks. He then uses his medical ninjutsu to systematically take down his opponent in order to disable and subdue them.

While in his Sage Mode, Kabuto's physical abilities, such as his speed and reflexes, were enhanced to the point were he could both evade and repel multiple high-speed and powered attacks from both Sasuke and Itachi with relative ease, despite having his vision impaired.

Medical Ninjutsu
Despite his age, Kabuto has demonstrated tremendous skill and ingenuity in medical ninjutsu. With his extensive knowledge of medical ninjutsu and of the human body, Kabuto can quickly adjust to any damage done to his body and severely injure a person with a single chakra-infused strike to the chest. He has also developed the unique ability to be able to reactivate dead cells and grow new ones; the usage of this technique effectively during battle requires him to read his opponent's moves accurately in order to prepare the area of which he would apply the cell reconstruction, a feat that he is very capable of. Through his experiments on Karin's healing abilities and powerful life-force, Kabuto was able to attain tremendous regeneration abilities himself.

He also often uses scalpels as throwing weapons instead of kunai. In Part II, Kabuto has apparently advanced his medical ninjutsu even further. He is capable of using the chakra scalpel without any hand seals, and still powerful enough to cut through wood and flesh with ease, and can use the Mystical Palm Technique at a distance.

Kabuto's medical ninjutsu has also led him to develop a series of drugs which he uses with great effect. For Sasuke, he gave drugs which aided in his training process. As shown with Manda II, he is also capable of genetically altering organisms making them bigger, stronger than the original. Kabuto has also invented a special drug that is capable of suppressing the power of a Wood Release user and a truth serum that allows him to interrogate enemies with ease.

Kabuto has demonstrated a unique affinity for corpses, and has demonstrated an interest in being able to reanimate them. This is primarily convenient when he is experimenting with test subjects, though they have been used briefly in escape situations, and may be used in combat. Kabuto's expertise in medical ninjutsu is far-reaching enough for him to be able to create an almost perfect copy of a person from a corpse in very little time and under high pressure, and keeps a sealing scroll to summon corpses for usage; he mentioned to Orochimaru that he would like to keep his stock refilled after using one. Kabuto can even use the small remains of a corpse to create an enhanced clone as he did with Manda by using the dead snake's cells and various drugs.

Summoning: Impure World Resurrection
As a further testament to his corpse theme, Kabuto can perform the Summoning: Impure World Resurrection technique — which only Orochimaru and Tobirama Senju could before, claiming superior usage of the technique than his predecessors, supporting that by resurrecting five deceased Akatsuki members at once. He also states that he can resurrect many other powerful ninja under his control, including Madara Uchiha. He applied a seal on the corpses that doesn't completely rob them of their free will, but still controls their body movement against their will — a seal different from the one Orochimaru used. Kabuto showed his great prowess in this particular technique by summoning a large group of famous and powerful shinobi, including deceased jinchūriki, Kage, and many others. He is even able to remotely monitor the bodies as well as re-write the commands given to the resurrected people, allowing him to rob them of their free will whenever he wants.

Snake Techniques
After implanting Orochimaru's cells into his body, Kabuto gained all of his snake-oriented techniques and abilities, first exhibiting some of these skills to kill several Takigakure ninja with great ease using multiple snakes. Kabuto is able to communicate telepathically with his snakes using the one that serves as his tail. He can also use the Hidden Shadow Snake Hands for a quick ambush attack. Moreover, with his new form, Kabuto is capable of injecting drugs that he has developed, directly through the fangs of the snakes that he creates from his body. He is also seemingly able to alter the size of these particular snakes at will, even after summoning them.

Another ability relating to this snake-theme is that Kabuto can shed his skin and turn into a white snake with arms, similar to Orochimaru's true form. While in this form, he can move at very fast speeds and even swallow a fully grown man whole.

To counteract genjutsu that are dependent upon eye contact, Kabuto can instead rely solely upon his snakes' ability to perceive their surroundings through sensing the ambient temperatures and smells using their tongues, rather than his own sight. After researching the Hōzuki clan's Hydrification Technique, through Suigetsu, he altered it so that he too could liquefy portions of his body at will, including the snakes that are generated directly from himself.

Senjutsu
After Orochimaru's death, Kabuto travelled across the world and ultimately discovered the location of the Ryūchi Cave. Here, he was taught senjutsu by the White Snake Sage and together with the research done to Jūgo's clan's abilities, gained access to a Sage Mode which, according to him, meant that he was a snake no longer, but had instead transcended into a dragon.

Physically, Kabuto undergoes little alteration in this form, with the only visible changes being the markings around his eyes extending onto his back and the growth of four horns on the back of his head, as well as darkened sclera.

While in Sage Mode, Kabuto's speed, perception and reflexes are enhanced to such an extent that he can even dodge the arrows fired by Sasuke's Susanoo, which are noted for their tremendous speed. He also gained access to further snake anatomy, such as their brille, which allowed him to severely impair his opponents through the use of intense light whilst remaining completely unaffected himself. He is also capable of infusing life into inanimate objects and manipulating them, such as the surrounding terrain, making it very difficult to counter.

Intelligence
As a former agent for Akatsuki, as well as being the right-hand man and spy for Orochimaru, Kabuto has gained access to large stores of knowledge which he uses for devastating effect. This includes him finding Tobi and his plan to revive the Ten-Tails, knowing about Zetsu, outwitting Kurotsuchi by knowing her abilities, and even the truth of the Uchiha clan massacre, the latter of which is so secretive that only a selective few ever knew.

Like his mentor Orochimaru, Kabuto has shown himself as an extensive researcher, performing multiple experiments to increase or neutralise an individual's abilities, as shown by his creation of Manda II, his intricate knowledge of the Wood Release, his mastery of the Summoning: Impure World Resurrection, the empowering of the Zetsu army, his enhancement of Madara's "golden age" body and the enhancements done to his own body by studying and reverse engineering the abilities of team Taka.

He has also shown himself to be a very skilled manipulator. For years, he was able to convince all of Konohagakure into believing he was a genuinely kind-hearted man with inept shinobi skill outside of medical skills (to which he made it appear he was only decent at) to make it easier in gathering information. He made Orochimaru doubt his true loyalties on at least one occasion, but since Orochimaru's demise, he has expressed his true support of his former master's ideology. He has shown to be able to use his strong powers of deception to fool his targets into aiding him in several manners, even including a master manipulator such as Tobi, well known for his own ability to manipulate others. He also used such manipulative methods with the Summoning: Impure World Resurrection, by allowing the revived to retain their personalities, so they can be used for psychological warfare, as well as memories, emotions, and creativity to enhance combat efficiency. This shows that Kabuto understands the human mind very well, and takes advantage of that to help meet his own ends.

However, Kabuto's present loyalties still remain unclear due to his many conflicting comments and actions.

Chūnin Exam Arc
Prior to the first phase of the Chūnin Exams, Kabuto befriends the members of the Rookie Nine with information on their fellow competitors. During the second phase of the exam, Kabuto joins forces with Team 7 in an attempt to finish the phase with little hassle. When the group encounters Team Oboro, Kabuto's glasses are knocked off of his face after saving Naruto from an attack. This causes Kabuto to momentarily lose his cool and reveal his Killing Intent, paralysing both Team Oboro and Sasuke and Sakura. This gives Naruto Uzumaki the opportunity to defeat the Ame genin. Upon completing the second test, Kabuto reunited with his team-mates, Yoroi Akadō and Misumi Tsurugi. Back with his team, Kabuto reports to Orochimaru what he has learned about Sasuke Uchiha.

With Orochimaru now in a position to observe Sasuke firsthand, Kabuto forfeits prior to the preliminary matches of the Chūnin Exams. While explaining to Naruto that he is fatigued, injured, and unwilling to risk his life further, Kabuto actually forfeits because he is afraid that prolonged fighting will cause him to show his true abilities, blowing his cover. After Orochimaru gathers enough of his own intelligence about Sasuke, he instructs Kabuto to kidnap Sasuke. He was able to take out the eight ANBU members guarding Sasuke and almost succeeded in accomplishing this task, but Kakashi Hatake intervenes before he could finish, forcing Kabuto to flee.

Later, he speaks with Baki and they discuss the upcoming Suna and Oto's invasion of Konoha. While discusing the upcoming invasion, they realised that they are spied by Hayate Gekkō. Kabuto offers that he will eliminate the spy, but Baki tells him that he'll eliminate Hayate.

Invasion of Konoha Arc
During the final matches of the Chūnin Exam, Kabuto kills and disguises himself as an ANBU member, and mingles with the audience. During Naruto and Neji Hyūga's battle, he heals Hinata.

When Sasuke injures Gaara, Kabuto uses a genjutsu to put the audience to sleep and signal the start of the invasion of Konoha. During the invasion, Kabuto has Oto ninja go after Naruto when he starts to pursue Sasuke, fearing what he will eventually become if he is not dealt with soon. However, it appears he already knew it would fail as he wanted to test Naruto.

He does not contribute in the battle, pointing out that Kakashi would only copy his abilities, and flees from the village when the invasion fails.

Search for Tsunade Arc
With Orochimaru being heavily injured as a result of the failed invasion, Kabuto accompanies him in searching for Tsunade, who they hope will be able to heal him. Upon finding and in time seeming to persuade Tsunade, Kabuto notices that Tsunade's medical techniques is filled with killing intent, and as such stops her before she can kill Orochimaru. With it clear that Tsunade won't willingly help them, Kabuto fights Tsunade in the hopes that he can force her into submission. After taking a Military Rations Pill to boost his abilities, Kabuto is able to keep up with Tsunade and land a number of disabling attacks, though she eventually lands a crippling attack upon him. Despite his efforts he realises that he is completely outmatched by the Sannin, Tsunade, even in her fallen state. Upon recovering, Kabuto uses a kunai to cut his hand, drenching Tsunade in his blood and invoking her haemophobia, allowing him to land a series of unopposed attacks.

When reinforcements for Tsunade arrive, Kabuto is pitted against Shizune, whom he quickly defeats. As he returns his attention to Tsunade, Naruto also comes to her rescue, surprised that Kabuto is a spy for Orochimaru. While Kabuto doesn't view Naruto as much of a threat, Naruto is able to hit Kabuto with his Rasengan, doing so much damage to Kabuto that he is unable to fully heal. While Kabuto had managed to strike a fatal blow to Naruto's heart before the Rasengan hit him, Tsunade heals Naruto before he can die, leaving Kabuto to lie on the ground, defeated. He later recovers to the point of helping Orochimaru summon Manda, and flees with his master once Orochimaru is defeated.

Sasuke Retrieval Arc
As Orochimaru anxiously awaits Sasuke's arrival at their lair, Kabuto encourages him to switch to a new body while he still can, even offering his own body. Although Orochimaru rejects the offer, Kabuto finds a strong body for Orochimaru to switch to just in case. Although his efforts seem to have been needless for a while, Orochimaru finally grows tired of waiting for Sasuke and switches to the body that Kabuto prepared. He also manipulated Kimimaro to leave to retrieve Sasuke, despite the latter's terminal illness.

Sasuke and Sai Arc
When Team Yamato comes to meet one of Sasori's agents, Kabuto is revealed to be that agent. Yamato, disguised as Sasori, is able to learn some things from Kabuto, though just as he is about to capture the latter Orochimaru shows up. Although it seems as though Orochimaru is about to kill Kabuto as a traitor, Kabuto cuts off the Sasori disguise's head, having intended to kill the actual Sasori under Orochimaru's orders. With his cover blown, Yamato calls to the rest of his team for assistance, and Naruto eventually starts to fight Orochimaru. At the start of the battle, Kabuto tries to attack Naruto who has slipped into his three-tailed form, though he is almost instantly repelled a good distance by one of Naruto's roars, knocking out Sakura in the process. He returns back to the bridge and heals Sakura, who had been attacked by Naruto, and hints that the Akatsuki is the greater enemy.

After the battle, Kabuto joins Orochimaru and Team Yamato member Sai in returning to their hideout, and Kabuto is tasked with leaving behind a dead body that looks like Sai to prevent anyone from following them. When Sai is later captured, Kabuto comes to his aid, only to be captured by Sai instead. Unable to escape, Kabuto is forthcoming with information, and discourages Naruto from trying to retrieve the traitorous Sasuke. Kabuto is left by himself as Team 7 searches the lair, though is at some point freed and joins Orochimaru and Sasuke when they depart.

Three-Tails Arc
Realizing that the time was fast approaching for him to change bodies, Orochimaru sent Kabuto to fetch Guren. When Kabuto nears her location Guren attacks him to see if he is worthy of being Orochimaru's attendant. Satisfied, she accompanies him to Orochimaru's lair and is left in charge of testing the prisoners there and forming a team.

When Guren and her team fail to kill a group of Konoha ninja, Kabuto has them help in summoning the Three-Tailed Beast. Kabuto ordered Guren to restrain it with her Crystal Release. When she proves unable to do so, Kabuto retreats upon realizing he needs to rethink their strategy.

Later, he begins preparations for a final attempt to capture the Three-Tails during which he secretly meets with Rinji, who is revealed to be a spy for Kabuto. After learning that Konoha has begun attempting to seal away the Three-Tails, Kabuto retrieves Guren and Yūkimaru to stop them.

While successfully stopping the Konoha shinobi from sealing the Three-Tails, they manage to obtain Yūkimaru, much to Kabuto's dismay. Deciding to take desperate measures, Kabuto tricked Kigiri, Kihō, and Nurari into thinking they were dying from the injuries they sustained from the Konoha-nin and convinced them to go through a gruelling operation of having cursed seals forcibly activated.

He then disguises himself as Rinji, tricks Yūkimaru to use his power to unleash the Three-Tail's full might despite knowing how weakened Yūkimaru was. After a failed attempt to have Yūkimaru make the Three-Tails go on a rampage, Kabuto, disguised as Rinji, reveals to Yūkimaru that it was Guren who killed his mother, but is shocked that Yūkimaru forgives her. He then attacks Guren and Yūkimaru with scalpels, but are deflected by Naruto. Naruto throws one of the scalpels cuts Rinji's face which turns out to be a mask and it falls off, revealing that he is Kabuto.

Since his meeting with Rinji, Kabuto has been posing as him. Kabuto and Naruto fight it out, with Naruto having improved enough to seemingly gain the upper hand over Kabuto. As Guren tries to escape with Yūkimaru, Kabuto then summons Rinji with his Dead Soul Technique to stop her. Guren fights him, only to be immobilized by his bats. Guren who made her promise to protect Yūkimaru at the cost of her life grabs Rinji from behind and sacrifice herself to kill him. Yūkimaru then screams in agony at what appears to be the loss of Guren. The screaming once again awakens Yūkimaru powers and causes the Three-Tails to breaks out of the seal and go on a rampage. Kabuto then leaves the scene satisfied with what was happening.

Itachi Pursuit Arc
After Orochimaru's defeat at the hands of Sasuke, Kabuto integrates remains from Orochimaru's body into his own. The remains start taking control of his body, and Kabuto is in a constant struggle to keep them from spreading. When he later confronts Naruto, Kabuto explains his reasons: he has always defined himself as someone's underling, never living for himself. By taking the remains of Orochimaru he can become strong enough that he need never serve anyone ever again. This being an emulation of Naruto's struggles with the Nine-Tailed Demon Fox, Kabuto gives him a book containing Orochimaru's information on Akatsuki in thanks. He departs before he can be apprehended, noting that he will someday fight Naruto after he avenges Orochimaru by killing Sasuke.

Konoha History Arc
After Naruto Uzumaki defeats Sabiru, Kabuto, hidden in some trees, kills him by throwing a presumably poisoned senbon to the back of his neck, so no information regarding who he works for would be leaked.

Confining the Jinchūriki Arc
Kabuto kills three Takigakure shinobi to test his control over his new powers. Satisfied, he heads to the Mountains' Graveyard, leaving a trail of bodies that the Anko-led Infiltration and Reconnaissance Party uses to follow him.

Once there he confronts Tobi, who is operating as "Madara Uchiha". Remembering that Kabuto was once Akatsuki's spy, Tobi tries to kill him for his traitorous actions. Kabuto responds by using the Summoning: Impure World Resurrection to revive five deceased members of Akatsuki, an incentive for Tobi to accept his help in the approaching Fourth Shinobi World War. In return, Kabuto asks that he be given Sasuke to learn the truth about ninjutsu.

Tobi asks what would happen if he doesn't accept, to which Kabuto responds by summoning a sixth coffin. Greatly disturbed by the coffin's contents, Tobi was forced to agree, though insists upon the condition that he not turn over Sasuke until after the war. The two head off to reformulate their war plans. In the anime, as Tobi was about to leave Mountains' Graveyard, Kabuto stops him and asks where he was going. Tobi replies that it was none of his concern, but tells him that he was going to Amegakure, to which Kabuto gives a devious smile after their brief conversation.

When Tobi receives intel on the location of the Eight-Tails and Nine-Tails, Kabuto offers to go capture them. Kabuto explains that he is interested in studying Yamato, the Nine-Tails' guardian. If Tobi would he prefer he not go, Kabuto says he would settle for a chance to study Zetsu. Tobi replies that he can have his own Zetsu to study if he manages to catch the Nine-Tails. Kabuto revives Deidara and together they fly to the Island Turtle upon one of Deidara's clay birds. As they get closer to the island Deidara creates clay clones of themselves, which the intercepting Third Tsuchikage attacks. The time this buys is short-lived, as the Tsuchikage himself was a rock clone; the Tsuchikage and his escorts confront the real Kabuto and Deidara.

While Deidara and the Tsuchikage exchange insults, Manda II seeks out and slows down the Island Turtle. To keep it from moving, Kabuto has Deidara hit it with an explosive squid. Kabuto goes ashore, leaving distracting the Tsuchikage to Deidara. Kurotsuchi pursues Kabuto and manages to catch him. Yamato then appears, creating a route for Aoba Yamashiro to get close to Kabuto and read his mind. Before Aoba is able to begin doing so, Kabuto sheds his captured body and kidnaps Yamato. He retreats into Manda II's nose and returns to Tobi, de-summoning Deidara in the process. When Tobi questions his failure, Kabuto explains that studying Yamato will allow him to make the White Zetsu Army stronger. Tobi accepts this explanation and tells Kabuto to get to work.

Shinobi World War Arc
Proposing to keep the drugged Yamato alive, so he may strengthen the White Zetsu Army further, Kabuto states that use of the Human Path wouldn't be necessary to extract information, as a combination of his truth serum and Tobi's Sharingan would suffice. With their forces amassed and modifications completed, Kabuto mobilises his revived shinobi to the main battlefields, with the exception of those he forms into a Surprise Attack and Diversion Platoon. After instructing the latter, Kabuto himself departs, capturing the surveying Anko after a brief battle. When Tobi later demands her death, Kabuto refuses on the grounds that the traces of Orochimaru's chakra in her could help improve his control over the resurrected shinobi, which was in their best interests.

Complying with Tobi's request to gain his approval, Kabuto demonstrates his technique using Fū as a sacrifice to resurrect Torune, accompanying it with a step-by-step explanation. Claiming that it had no weaknesses, he reveals the few methods able to halt the technique, before leaving the apparently satisfied Tobi. However, Kabuto is unconcerned by his recent admissions, due to the possession of another technique and the prospect of soon learning the secrets of the Sage of Six Paths. A now isolated Kabuto then starts to drain Anko's chakra, acquiring an incredible increase in power, just as a number of the revived shinobi encounter the Third Division.

Erasing their consciousness soon after they make contact with the division, he commands the assault to begin. After seeing how retaining their emotions could cause the revived shinobi's defeat, Kabuto remotely subdues as many as he can, leaving only those whose individualities may present an advantage intact. Directly interfering as the need arises, he later has Gari and Pakura summon the previous generation of the Seven Ninja Swordsmen of the Mist, to retain Akatsuki's superiority. However, despite having Haku intercept Kakashi and much to his shock, Zabuza Momochi and his crucial technique are ultimately defeated.

Elsewhere with Mū's discovery on approach to the Fourth Division, Kabuto has him summon the Fourth Kazekage, Second Mizukage and Third Raikage, just as more of his forces engage the First Division. He then leaves them to their own devices, believing that taking their identities could hinder their fighting capabilities. This backfires in the case of Hanzō, who contradicts Kabuto's control before he can intervene, handing victory to the opposing Fifth Division.

When Tobi goes out of the way to acquire the sealed Gold and Silver Brothers from the Allied Forces, Kabuto deduces that Tobi wants the Nine-Tails chakra within them. However, Kabuto instantly realises that Tobi only has one of the Eight-Tails' tails so he couldn't understand what Tobi was planning.

Later, during the second day of the War, he reacted in shock when Naruto Uzumaki in his Nine-Tails Chakra Mode defeated Toroi near instantly with a Rasengan. Pleased at the prospect of finding Naruto and Killer B before Tobi, he thought happily of how he would be able to manipulate Tobi in exchange for them and wished that he could see the look on his face, but lamented that his mask hid it. As such, he has Itachi and Nagato, who up until now had been talking to Naruto and B, attack them immediately in the hopes of turning the tides of the battle in his favour.

When Itachi attempts to attack Naruto with his Mangekyō Sharingan, the crow Itachi had implanted within Naruto comes out, and stops Itachi, who then begins attacking Nagato and his summons, much to Kabuto's surprise. When Kabuto learns the crow had Shisui's eye, he gets excited about the prospect of collecting it, and removes Nagato's consciousness, completely taking control of him. As Kabuto watches on he decides to kill the jinchūriki temporarily and store their souls in the King of Hell and then revive them later, just as long as he got his hands on them before Tobi did. He later remembers that he should capture Itachi who had escaped his control as well. After Nagato is sealed, a visibly angered Kabuto laments Nagato's lack of mobility due to his injured legs, and comments that he was unable to see the last attack due to Itachi blinding the Giant Snake-Tailed Chameleon and King of Hell with kunai. He then resigns himself to unleashing his "prized possession" and grins menacingly, letting his serpentine tongue stick out in true Orochimaru fashion.

As part of the Fourth Division faces the Third Raikage, Kabuto reveals that he simply used him in order to buy enough time to accomplish the summon of "that guy", before then deciding to eradicate the Raikage's personality. Once again setting his sights on the acquisition of Naruto, he resorts to activating the Raikage's "strongest spear" after prior attempts at incapacitating him result in nothing but failure, in spite of being aware of the considerable risk of injury it poses towards his target. Afterwards, Kabuto is relieved that "Mū" was sealed before he could reveal his means of escape to Ōnoki. However, due to his splitting, he says it will take a bit longer to summon "that". After some time passed, Mū used the Summoning Technique to get Kabuto's trump card into play, which is later revealed to be Madara Uchiha, whose name Tobi has been using as his own.

After devastating the battlefield, Kabuto marvels at the power of someone near that of the Sage of the Six Paths. When Madara asks him again how much he knew about him, Kabuto tells him that he realised that Madara didn't die during the battle with Hashirama at the Valley of the End. He then tells him that he did not know the details of his and Tobi's plans but he somehow doubted that Tobi would act as planned. He then informs Madara who tried to summon the Nine-Tails that it resided within a host. Visibly pleased with himself, Kabuto thinks that if he could effectively manipulate Madara, he could control the battlefield.

As Kabuto, still in control of Mū has him attack the remainder of the Fourth Division alongside Madara, Mū is buffeted by A's attack. As Mū emerges from the rubble, to see Madara engaging the five Kage, he is pursued by Dodai and the Hokage Guard Platoon. As Mei envelops the battlefield in mist, Kabuto positions Mū directly in front of Madara. Thinking that if Ōnoki was in fact making A lighter, then his attacks would not have any weight behind them. Despite this theory, Mū is knocked away by A much to his shock.

As the battle between the Kage and Madara continue, Kabuto while having Mū evade the Hokage Guard Platoon and Dodai thinks to himself that there weren't shinobi in the world as powerful as Hashirama, whose power was once thought to be a mere myth — just as the Sage of the Six Paths was. He later muses to himself as Hashirama's face is revealed to be jutting out of Madara's now-exposed chest that the combination of two of the most powerful shinobi in the world was his trump card.

With his location uncovered by Itachi, Kabuto commends him for doing so despite the barrier he had erected, before being told that the source of where his chakra came from could be vividly felt whilst under his control. Reminding Itachi that he couldn't be killed if he sought to stop the technique, Kabuto breaks into maniacal laughter upon sensing Sasuke and declares that his luck had finally changed. Excited that his reward for his part in the war had come to him by choice, he tells Itachi that he'd love to explain the Summoning: Impure World Resurrection technique at length, but that he didn't think Sasuke would stay quiet for that long. He then tries to use Sasuke's hatred to tempt him into assisting with Itachi's defeat, however, Sasuke instead chooses to side with his brother. With this, Kabuto prepares for battle stating that it'd be an interesting event.

Closing his hood, he states that he was an introverted person and as such, was unsettled by so many people staring at him, before sending his snakes towards Sasuke and Itachi. Although the brothers are able to fend off the attack, Kabuto uses this opportunity to hide in one of his snakes, where he then discloses the unique abilities that he gained from his experimention on Sasuke's former team-mates: Karin's healing abilities, a similar ability to Suigetsu's ability to transform into water and Jūgo's ability to absorb natural energy. After revealing that he had both found and trained at the Ryūchi Cave, he narrowly evades Sasuke's attack, stating that his perception skills had been greatly enhanced as well. Emerging from the snake's mouth, he reveals that he had finally surpassed Orochimaru upon becoming a sage and declares that he was no longer an imperfect snake, but instead — a dragon.

Attacking the brothers using the Sage Art: White Rage Technique, Kabuto lowers the brille of his eyes and liquefies his insides, so as to move unimpaired despite the technique's effects. First intending to target Itachi and rewrite his tag, he changes his mind at the last minute and opens his mouth wide, seemingly intent on swallowing Sasuke whole. When Itachi interferes, Kabuto questions if he was able to sense him but Itachi denies this, stating that it was Nagato who had done so previously. Kabuto then remarks on Itachi's skills in understanding and deceiving others in an apparent attempt to lay doubt and mistrust amongst the brothers, before dodging an attack from Sasuke — by retreating to the roof of the cave — and declaring that such a makeshift duo could never defeat him.

Curiously observing the brothers from the cave's ceiling as they formulate a new strategy, Kabuto is soon enclosed by Itachi's assault, allowing Sasuke to pin his snake-tail to the rock. Seemingly moving to use Sasuke's sword to sever his own tail, he instead intercepts and impales Itachi with the blade, just as his liquefied tail begins to slip free. However, when Itachi suddenly disperses into a flock of crows, Kabuto's horn is severed in the ensuing counter after Itachi commandeers Sasuke's sword, but he simply remarks that he had yet to get used to possessing horns.

Amused that such previously hostile brothers could be so coordinated, Kabuto discerns from Sasuke's responses that he must have learnt the truth surrounding Itachi after the latter's death. Noting the contradiction between the siblings aims, he again tries to tempt Sasuke into betraying Itachi given their mutual desires for Konoha's destruction. When Sasuke rejects this, Kabuto recounts his past as a spy and how he was discarded once he began to lose track of his real identity amongst the fabricated ones, gaining nothing in exchange but shame and dishonour. He then reasons that no one understood Sasuke better than him and so, they should stand together as brothers, but Itachi warns of Kabuto's skill in deceit. Declaring the reasons for his own and his technique's invincibility, Kabuto activates his chakra scalpel and charges at the brothers, before clashing with and repelling Itachi.

Declaring that the pair were severely underestimating him, Kabuto uses his Sage Art: Inorganic Transmigration technique to manipulate the surrounding cave formations in order to attack them. Incapacitating Itachi — who had instead protected Sasuke — Kabuto retrieves a talisman from his snake, intent on overwriting Itachi's mind. However, before he can do so, he is stopped by Sasuke who creates a ring of Amaterasu around himself and Itachi. Assessing Sasuke's choice of defence, Kabuto affirms that there was no way they could defeat him because he had come closest to the Sage of the Six Paths than anyone in the world. As Itachi tells Kabuto that he was bound to fail as he did in the past because he didn't know who he truly was, Kabuto states that for his entire life he had been trying to find his real self, in his own way and that from the very beginning he had nothing.

Naruto Shippūden 2: Bonds
Kabuto makes a small appearance along with Orochimaru. He tells Sasuke how Konoha had been attacked by the Land of the Sky, at which Sasuke told him he doesn't care. Orochimaru then ordered him to get a scroll and capture Shinnō. In the end, Sasuke failed to bring Shinnō, at which Kabuto was shocked.

Video Games
Kabuto plays a role in the Story Mode of Naruto: Clash of Ninja Revolution 2, set during the pre-Shippūden filler arcs. He first appears as a shaded figure talking to Bando about his and Kagura's plot to destroy Konoha. When Bando questions Kabuto's motives in the plan, Kabuto simply replies that he has been rather bored lately and is just in it for kicks. Kabuto witnesses Kagura's defeat at the hands of Tsunade and attempts to flee only to be pursued and attacked by Naruto. During the fight Naruto defeats Kabuto with his Rasengan. Accepting defeat, Kabuto escapes, assuring Naruto that their next encounter will end differently.

In Naruto Shippūden: Ultimate Ninja Heroes 3, Kabuto and Kabuto with Orochimaru's remains are featured as two different people. In Naruto Shippūden: Ultimate Ninja Storm Generations, Kabuto with Orochimaru's remains is playable.

Trivia

 * "Kabuto" is the last part of the Japanese name for Aconitum, a plant that can either alleviate pain or kill, which seems fitting as he is a medical-nin who uses his medicinal knowledge in battle.
 * A kabuto is the name for a samurai's helmet or headplate. With his former team-mates, Yoroi ("armour") and Tsurugi ("sword"), they form an armour-helmet-sword trio.
 * His family name,, is the short form of the Japanese name of the Medicine/Healer Buddha (long form: Yakushi nyorai), Bhaisajyaguru, and means "medicine user".
 * According to the Third Databook:
 * Kabuto's hobby is taking care of his scalpels.
 * Kabuto wants to fight Naruto and Orochimaru.
 * Kabuto in Konohagakure has completed 191 official missions in total: 163 D-rank, 28 C-rank, 0 B-rank, 0 A-rank, 0 S-rank.
 * Kabuto's favourite phrase is . This proverb refers to innumerable changes or infinite variety.
 * His favourite food is jack mackerel grilled with salt and sea bream grilled with salt while his least favourite food is raw meat.
 * When chapter 521 was first published in Weekly Shōnen Jump, Kabuto was illustrated without his glasses after he left Tobi. This is later corrected in the tankōbon version of the manga.
 * In Japanese mythology, dragons and snakes are pretty much the same thing. Snakes are just weaker versions. In fact, the most well-known snake in Japanese mythology, the Yamata-no-Orochi, is actually also called a dragon. Kabuto 'becoming' a dragon instead of a snake simply means he upgraded, not that he changed species.

Quotes

 * (To Naruto) "Little kids think life is so easy. That's why they go on and on about their dreams. That's why they never give up."
 * (To Naruto) "You've just thrown it all away! Dreams don't come true when you're dead!"
 * (To Naruto) "Hehehe…, you can't beat me. You have no skills, unlike Sasuke."
 * (To Naruto) "After Orochimaru died, I found myself not knowing who I was, again… Without knowing parent or country, I was taken in by the enemy… Since a young age I've moved about countries and villages as a spy… To me, things like countries, villages… they hold no firm reality in my mind. That was, of course, until I found myself under the wing of Orochimaru… but that presence is gone again. What am I anyway… The pain of not having an identity… I'd think you should understand… Naruto."
 * (To Naruto) "I decided I wished to be like you as well, Naruto, and for that reason… with Lord Orochimaru now integrated into this body, I plan on finding a new "me", one stronger than Lord Orochimaru himself! Finding a new me, that is the lesson you taught me."
 * "Orochimaru is the symbol of reincarnation, and as a goal, a greatness meant to be exceeded by me. He'll continue to live inside me."
 * "Lord Orochimaru immediately tried to acquire that power… but… he didn't yet possess a body that could tolerate it… That's why he couldn't become the Sage that I have become!"
 * "I am no longer a snake… Sage power has allowed me to shed that skin… and I am a dragon now!!"
 * (To Itachi) "My name is a code… My glasses are a tool… I've been no one… From the start. From the very start… I had nothing."