Tobi

, who posed as when first introduced, is a co-founder of Konohagakure, Akatsuki and was once the leader of the Uchiha clan. When he joined Akatsuki as Tobi, replacing Sasori, he was partnered with Deidara, revealing himself as Madara after Deidara's death. He has been recognized by Kisame Hoshigaki as once being the Mizukage of Kirigakure, although it is unknown when. He is a major antagonist of the series, being responsible for the Nine-Tails' Attack on Konoha, and being involved in the Uchiha Clan Massacre.

Background
About eighty years before the Fourth Great Shinobi World War, Madara grew up in constant competition with his younger brother, Izuna Uchiha, who were both known as the most gifted members of their clan. Their competition led to both gaining the Mangekyō Sharingan, and, with it, they were able to take control of the Uchiha clan, Madara acting as its leader. Even by his clan's standards, Madara's chakra was unusually strong. In an age defined by war, all he did was battle, and still he sought to become even stronger. Under his leadership, the clan conquered all they came across. Over time, he began to lose his sight because of the Mangekyō Sharingan. To regain his vision, he took his brother's eyes (an act Madara said his brother had consented to), and gained the Eternal Mangekyo Sharingan, allowing him to continue to lead the Uchiha to prosperity.

In the years that followed, the Uchiha constantly clashed with the equally powerful Senju clan. To bring an end to the constant fighting, the leader of the Senju, Hashirama Senju, approached the Uchiha with an offering of peace. Although Madara never wanted peace with the Senju, the rest of the Uchiha wanted to end the fighting, and Madara had no choice but to go along with their decision. The Senju, the Uchiha, and all the clans they had conquered came together to form the village of Konohagakure. Against Madara's wishes, the villagers selected Hashirama as the village's First Hokage. Madara feared that Hashirama would oppress the Uchiha, and tried to rally support for challenging his leadership. Rather than help him, however, the Uchiha turned their backs on him, believing his only motives were due to pride and the desire for more power.

Abandoned by his clan, Madara left the village, later returning in order to challenge Hashirama in battle. They fought at the site that would someday be called the Valley of the End, where, although Madara called upon the Nine-Tailed Demon Fox, he was defeated, and was believed to have died. Madara faded into memory, and, in time, would found Akatsuki and become Kirigakure's Mizukage. He also appears to have fought Ōnoki, the Third Tsuchikage at one point in his life as noted by A, the Fourth Raikage, although the results of that battle were left unclear.

Twelve years before the start of the series, the Nine-Tails attacked Konoha. Although Madara denied having had any involvement in the attack, Itachi Uchiha and Minato Namikaze said that the Nine-Tails was under Madara's control at the time. A few years later, he infiltrated Konoha to try and rekindle the flames of war. He was found by Itachi first, who convinced Madara to spare the village in exchange for helping to wipe out the Uchiha clan for deserting him decades earlier. Madara complied, training Itachi and providing assistance. Itachi never truly trusted Madara, however, and kept an eye on him for the rest of his life. Madara also met with Danzō around the time of the massacre, but did not see each other again until after Danzō fled the Kage Summit.

Tobi
To keep in Akatsuki's shadow, Madara eventually took on the disguise of Tobi, giving orders to Pain in secret. He wears an orange, swirl-patterned mask that reveals only his right eye. When he trained Itachi, he wore a slightly different mask with black flame-like patterns on it, and he had longer hair than he does now. His hair is cut short from the days of Konoha's founding, and he wears a uniform consisting of a number of bolts and pins, which is usually concealed by his Akatsuki cloak.

While acting as Tobi, he is carefree and goofy, something that annoys most of the other members. Deidara, who believed all within Akatsuki should be serious and calm, was not pleased with Tobi's childish personality, and frequently attacked the latter in a comedic fashion when annoyed. Apparently, Madara is very committed to keeping his identity secret, as he has been seen keeping up his goofy appearance even when no-one was around (at least during the anime's filler arc). Kisame and Zetsu, on the other hand, somewhat appreciate Tobi's ability to brighten up a gloomy organization such as theirs. However, once his identity is revealed to everyone in Akatsuki, "Tobi" has abandoned his goofy nature and adopted Madara's personality.

Personality
Compared to his Tobi personality, Madara's true personality is considerably calmer and much more serious, but he still has a habit of joking around and disrespecting everyone around him. Despite his current limitations in battle, he is extremely arrogant, insulting even the strongest ninja and treating Akatsuki members as mere tools. While speaking derogatorily to Pain he still recognized his power as the strongest in Akatsuki and for possessing the Rinnegan. There are only a handful of exceptions that he admires, the most prominent being Hashirama Senju.

Madara has shown great ability in manipulating others to do his work for him. Minato believed that he was using Pain's ideology against him in order to control him. He similarly befriended Sasuke in order to get him to join Akatsuki by telling him about Itachi's past, even though he has an apparent interest in Sasuke and his abilities. He appears to have a somewhat twisted outlook with respect to this, often avoiding responsibility by claiming that people acted voluntarily when they were really coerced or manipulated by him.

Madara has set his goals in getting Sasuke on his side to serve Akatsuki's goals. As such, he was pleased that when Itachi died, no one would be able to prevent him from telling Sasuke the truth of the Uchiha Clan Massacre. Madara expressed disappointment when Sasuke failed to retrieve the real Killer Bee, and was worried that he may not be easy to control. However, whenever Sasuke enters deeper into the darkness of revenge, Madara shows delight, the most prominent being when Sasuke's hatred fully develops Susanoo, and when he sacrificed Karin to pierce Danzō's heart.

Madara possesses an extreme hatred towards the Senju clan and the Senju-led Konohagakure, as he is a descendant of the elder brother who was passed over being the successor of the Sage of the Six Paths. This hatred was compounded when the village chose Hashirama Senju to be Hokage over him. Madara admired Hashirama the most for his power, but still hated him. This hatred led Madara to a life dedicated to revenge. Madara believes that all Uchiha are destined to walk the same path of revenge against the Senju and Konohagakure, and that Naruto, who has inherited the Senju's Will of Fire, is fated to battle Sasuke, who has inherited the Uchiha's hatred, even if Madara himself must force them to do so.

Perhaps as a consequence of his old age, Madara seems to enjoy sitting down and taking his time with things, especially when telling stories, just like he told Itachi's story to Sasuke and his Moon's Eye Plan to the Kage and the samurai.

Abilities
Most of Madara's abilities are still unknown. He has the strongest chakra of any Uchiha to ever live and is widely regarded as one of the most gifted ninja in history. He was described as a "very powerful ninja" by Minato Namikaze himself. He has also been noted to have been born with particularly powerful chakra, which he states is the reason for his "stubborn refusal to die". Even the Nine-Tails mentioned that Madara's chakra is even more sinister than its own. One of the abilities he has actually displayed is his speed, which, as Tobi, was apparently his only claim to fame. To that end, Kisame commented "he is a good runner". Madara also appears to have immense strength, as he was able to stop a slash from Suigetsu's giant sword with a single arm, as well as crush his own infected arm clean off with his other bare hand. Ōnoki has alluded to Madara's power from before he took on the guise of Tobi by stating he shouldn't have to work from the shadows considering his power and skill. Madara also shows to have vast knowledge and intelligence; just from analyzing his opponents using a jutsu once, he can identify that person as well as recognize and understand how their jutsu work. He also was able to counter-attack Fū and Torune's decoy plan to turn it against themselves.

He was armed with a giant kusarigama with a war fan attached to it during the time of Konoha's founding, fitting with his clan's name, which means "paper fan". He is also said to have been able to summon the Nine-Tails. It is unclear if this referred to the use of the Summoning Technique or if he could produce enough human malice to bring it to his location.

However, despite all the high-caliber power he has shown so far, Itachi and even Madara himself both claim that the wounds he received from Hashirama Senju has left him powerless, an empty shell of his former self.

Teleportation
Madara shows the ability to completely avoid damage from most attacks. After being slashed across the midsection by Sasuke's sword, he collapsed, only to stand up again a few seconds later and complain about the speed of the attack. The same things occurred when Naruto hit him in the back with a Rasengan, where the attack literally phased through him, avoiding damage. His ability's consistency is confirmed when Sasuke attempted a Chidori on him, and, as predicted, he phased through Madara as he had done earlier. Although he can use teleportation to move parts of his body through a dimension he is still susceptible to a counter attack as stated by Fū. Throughout the whole series, after his fight with Hashirama Senju, he has only known to have been damaged once: in the fight with Danzō's henchmen. Before he "absorbed" Torune, Torune apparently touched Madara's right arm, getting it infected with nano bugs and therefore forcing him to remove it.

Madara also shows the ability to travel long distances within relatively short timespans, escaping the final explosion created by Deidara and reappearing in Amegakure within a very short period. It was speculated by Kakashi that he uses spacetime Ninjutsu to instantly send himself or even parts of his body to different locations or some sort of void and then instantly bring them back. It is revealed that Madara can find the exact location of a person and warp himself to that place, stating that it is in his power. He has also shown the ability to teleport others, apparently to a separate dimension or area and store them there. He uses that ability in the battle against Torune and Fū to simply make them disappear so that Sasuke could fight Danzō. His right eye appears to be the basis for this transportation.

Sharingan
Madara had mastered his Sharingan at a young age, and received praise for that. Even after being scarred by Hashirama Senju and losing a great amount of power, his Sharingan can still see the color of chakra, as he saw the Poisonous Nano Bugs Technique spreading through Fū. Due to his mask covering the left side of his face, Madara only has been shown with his right Sharingan.

Mangekyō Sharingan
During Itachi's fight with Sasuke, it was revealed that Madara Uchiha and his younger brother, Izuna, were the first members of the Uchiha to activate the Mangekyō Sharingan, he then used his new profound power to take over the Uchiha clan. After going blind because of the use of the Mangekyō Sharingan, he implanted his brother's eyes into his own body. Madara then awakened a new "Eternal" Mangekyō Sharingan, making him the first and only character in the series to have an "Eternal" Mangekyō Sharingan, a combination of his own and Izuna's Mangekyō Sharingan. With it, Madara never had to fear the risk of losing his eyesight again. Madara's knowledge and mastery of the Mangekyō Sharingan gave him the power to forcibly subdue the Nine-Tails and the Eternal Mangekyō Sharingan allowed him to fight on par with Hashirama. Itachi during his fight with Sasuke stated that Madara's ocular powers are intact, which implies that he may still be able to use his Eternal Mangekyo Sharingan. Despite having the Eternal Mangekyo Sharingan, he has yet to be seen using it in the current Shippuden time-line.

Rescue Gaara arc
After the death of Sasori, Madara, as Tobi, appeared with Zetsu collecting Sasori's ring. He expressed interest in joining Akatsuki, believing that finding the ring would grant him membership. They then found Deidara's arm and the ring it wore, believing Deidara to be dead too. When Deidara appeared and demanded that Tobi give him his arm back, Tobi refused, prompting Deidara to comedically try and choke him to death with his legs.

Three-Tailed Beast arc
Tobi was accepted into Akatsuki as Sasori's replacement and Deidara's new partner. He was assigned to capture the Three-Tailed Giant Turtle, and Deidara accompanied him. In the anime, during their search, they stopped to get a bite to eat at a dango shop, and Deidara waited anxiously for Tobi to remove his mask so that he could see what he looked like underneath, but he turned away, hiding his face. When he finished his dango, they split up and went in different directions. Tobi eventually found the lake and saw Sakura, Shizune, Hinata, and Ino on the lake using the Four-Corner Sealing Barrier. He then figured out that the technique was to seal the Three-Tails, and went after Deidara to inform him of his discovery. After Tobi watched Deidara kill two ANBU, he congratulated him. They both discovered the Three-Tails inside the lake. Deidara used his clay to make it appear outside, after which Tobi tried to convince Deidara to fight it in his place. The beast began chasing him, and Deidara used one of his bombs on it while it was distracted. The rest of the battle went unseen. Afterwards, Tobi started talking about how his jutsu was flawless, and now he understood why he had been assigned to the mission. Deidara retorted that he wouldn't have got far without his clay. Tobi later fell asleep atop the Three-Tails after making another cheeky comment, much to the anger of Deidara, who "woke him up" by detonating a clay bomb next to him.

Hunt for Itachi arc
Before sealing the Four-Tailed Monkey, Akatsuki learned Sasuke Uchiha had defeated Orochimaru. Once the sealing was complete, Deidara, angry that he had not got to kill Orochimaru, brought Tobi with him to kill Sasuke instead. They found and confronted Sasuke, and Tobi was given the job of providing assistance for Deidara during the battle. After some initial taunting from the duo, Sasuke surprised them both with his extreme speed and ran his sword straight through Tobi, apparently disemboweling him. Tobi then suddenly stood up again, complaining about the speed of the attack. The battle ultimately didn't go in Deidara's favor, so he used C0 in an effort to kill Sasuke at the loss of his own life. Zetsu reported to the remaining members of Akatsuki that Tobi had been killed too, prompting Pain to remark that he was easily replaceable.

It was soon revealed, however, that Tobi had survived, as he met with Pain and Konan in Amegakure. Tobi was now shown in a completely different light, and was revealed to actually be Madara, the real leader of Akatsuki. His entire demeanor and personality had changed during the appearance. He commented that Sasuke was developing nicely, and then instructed Pain to capture Naruto Uzumaki, the host of the Nine-Tails. He later appeared to distract the 8-Man Squad as Tobi while Sasuke fought with Itachi. The Konoha ninja had no success in striking him with their attacks, so Shino Aburame volunteered to fight Madara one-on-one. With his bugs, Shino was able to box-in and catch Madara, but Madara was able to escape from this as well. Zetsu then arrived to inform him that Sasuke had killed Itachi. Madara pointed out that he had known that this would be the outcome, and went to see Sasuke. Before leaving, his Sharingan was spotted by Kakashi.

Madara tended to Sasuke's wounds and, when he woke up, offered to tell him about Itachi. Madara tried to befriend Sasuke by removing his mask and revealing his Sharingan, something that caused Itachi's Mangekyō Sharingan to form in Sasuke's left eye and which made him use Amaterasu on Madara, who quickly retreated into the darkness of the cave. After stopping the black flames, Madara then appeared again with his mask back on, and began to muse about how Itachi never ceased to amaze him. After Sasuke asked what he was talking about, Madara revealed that Itachi had most likely set it up so that the sight of his Sharingan would trigger the Amaterasu he had sealed within Sasuke. After Sasuke complained that he was making no sense, Madara revealed that it was to protect him, and, when Sasuke still didn't believe him, Madara said how it all must sound crazy but assured him that he was telling the truth, and introduced himself as the man who had helped Itachi on that fateful night. He told Sasuke about the Uchiha clan's history, Itachi's secret life, and the lengths he had gone to keep Sasuke and Konoha out of harm's way. Sasuke, regretting that he had killed Itachi now that he knew the truth, resolved to destroy Konoha for forcing Itachi into the life he had lived.

Hunt for the Eight-Tails arc
Madara convinced Sasuke and the other members of Taka to start working with Akatsuki, the two groups having Konoha's destruction as a mutual goal. Before they could do that, however, he stated that Akatsuki needed the two remaining tailed beasts. Since Pain was still working on capturing Naruto, Madara sent Taka to capture the Eight-Tailed Giant Ox. After Taka left, Madara spoke with Zetsu, discussing Akatsuki's actions up to that point. He went on to say that, although they had lost five talented ninja in Akatsuki, all of their efforts had brought him closer to "making Sasuke his".

After Taka captured the Eight-Tails' host, Sasuke gave it to Madara for Akatsuki to seal. During the extraction process, it was revealed to be a fake. Madara was shown to remain silent, as Kisame commented that Sasuke had been fooled in the latter's attempt to capture the jinchūriki.

Five Kage Summit arc
Zetsu informed Madara of Nagato's failure to capture Naruto, his betrayal of Akatsuki, and his sacrificing himself to revive the Konoha villagers he killed. Irritated by the constant setbacks as well as Nagato's wasting the Outer Path: Samsara of Heavenly Life Technique, Madara sent Kisame to capture Killer Bee. Then went to confront Sasuke, who was taking Taka to Konoha. Madara told them they are wasting their time, Nagato having already destroyed the village, but convinces Sasuke to go to the Kage Summit to kill Danzō, the new Hokage and a conspirator in the Uchiha's assassination. Madara instructs Zetsu to lead Taka to the Land of Iron, but when they arrive he has Zetsu reveal their presence to the Kage.

While Sasuke fought the Kage, Madara meet with Naruto, who was also in the Land of Iron. He tried to figure out how Naruto was able to cause Nagato to have a change of heart, but was caught by Kakashi Hatake and Yamato. Rather than fight, Madara told them about the Sage of the Six Paths, the truth of the Uchiha clan, and Sasuke's descent into darkness. They doubt the validity of what he told them, but he persevered, saying that Naruto and Sasuke are destined to fight some day before disappearing.

As Sasuke was about to be killed by the Kage, Madara rescued him. He sends Sasuke away while having Karin go with him to heal his injuries. Madara voiced his disappointment that Sasuke was not more of a match for the Kage, having hoped to take them hostage to facilitate with his plans. He was nevertheless happy by the development of Sasuke's Mangekyō Sharingan. He then explained his Moon's Eye Plan to four of the five Kage at the Land of Iron: his intention to reform the tailed beasts back into the Ten-Tailed Beast. He would then become its jinchūriki and use its power to place the world under his control with an. To that end, he asked the four Kage to give him Killer Bee and Naruto. They refused, so he declared the start of the Fourth Great Shinobi World War before disappearing.

Madara intercepted Danzō while he was fleeing the Summit. Danzō has his bodyguards, Fū and Torune, fight Madara while he prepared himself. Although forced to remove his arm during the battle because of Torune's Poisonous Nano Bugs Technique, Madara was easily able to dispose of the two. Madara then teleported Sasuke and Karin to their location, showing Sasuke that he keeps his word by giving him Danzō. Madara observed the battle and was glad when Sasuke is finally able to fully develop Susanoo. When Danzō displayed his numerous Sharingan eyes and his Wood Release abilities, Madara surmised that this meant he wanted to be able to control the Nine-Tailed Demon Fox. Madara also identified how Danzō is able to survive a battle with Sasuke: Izanagi. Sasuke and Danzō eventually clash, but Sasuke overcame Izanagi and mortally wounded Danzō.

Pleased with the outcome, Madara indicated that he wanted to take Shisui's eye, which was implanted in Danzō's right eye-socket. Before he can take it Danzō took Karin hostage, and Sasuke has no hesitation in cutting through her to finally kill him. As he died, Danzō activated the Reverse Four Symbols Sealing Technique in an attempt to take Madara and Sasuke with him, but Madara recognized it in time to escape while also warning Sasuke. Sasuke then stated they would head to Konoha. Madara however adviced Sasuke not to be reckless, and that despite Karin healing his more serious wounds, he was still very battered and needed time to recover. He then grabbed Danzo's corpse and also advised Sasuke to kill Karin if he truly has no need of her anymore since she knew too much about them. Sasuke merely stated he has never considered himself an ally of Madara. Madara brushed off the comment and teleported away with Danzo. At his lab, where a giant wall with many glass containers, each holding a Sharingan eye in a fluid, Madara cursed Danzo for destroying Shisui's Sharingan before dying as a final act of both duty and to spite Madara.

Trivia

 * The phrase "Tobi is a good boy" has proven to be very popular among the Naruto community. Although not said by Tobi himself (Zetsu's white half actually uttered the phrase to his black half after stating Tobi's intentions of joining Akatsuki wasn't so simple to accomplish), many have found the comment to be rather hilarious and, as such, Tobi is depicted as a carefree child or a good-natured character in many fanmade art and videos on YouTube while incorporating the phrase or a parody of it.
 * can be translated as "spots". Tobi can be translated as, or as . The latter translation connects Tobi with Taka through the Japanese proverb , meaning that an extraordinarily gifted child can be born from ordinary parents.
 * Tobi's first two video game appearances are in Naruto Shippūden: Ultimate Ninja Heroes 3 and Naruto Shippūden: Ryujinki.
 * Tobi's mask made a cameo appearance in the ending omake of Shippūden Episode 129 along with Baki's face and Haku's mask.
 * Tobi appears to have a liking for dango as seen in episode 99.
 * Madara makes a brief appearance at the end of the third Naruto OVA special, Naruto: The Cross Roads with Sasuke wearing an Akatsuki cloak.
 * According to the third Naruto databook (despite Tobi and Madara being the same person, the databook gives them separate entries):
 * Madara's hobby is falconry. As Tobi, his hobby is accompanying "Deidara-senpai".
 * Madara's favorite food is inarizushi, while his least favorite is roe.
 * Madara's favorite phrase is . As Tobi, his favorite phrase is given as.

Quotes

 * (To Pain and Konan) "The true power of the Sharingan... this Madara Uchiha's power!" ("Sharingan no hontou no chikara ga... kono Uchiha Madara no chikara ga!")
 * (To Naruto while talking about Sasuke) "The Uchiha is a clan destined for revenge..."
 * (While addressing four of the five Kage) "In that case, I hereby declare... the Fourth Ninja World War."
 * (To Pain and Konan) "Soon... soon all our goals will be achieved... and when they are, everything will be as it should."
 * (To Sasuke) "You have to have patience if you want to achieve your goal."