Itachi Uchiha

is is Sasuke Uchiha's older brother, and a missing-nin from Konohagakure, and a prominent member of Akatsuki, partnered with Kisame Hoshigaki. He and Kisame were the first active Akatsuki members to appear.

can be translated as "weasel". To some degree of Japanese belief, weasels are considered a harbinger, often signifying ill fortune (possibly a reference to his murder of his family and the rest of his clan). His surname, Uchiha, is another way of pronouncing uchiwa, or a "paper fan", which is actually the Uchiha clan symbol. An uchiwa can be used to fan flames, making the flame hotter, referring to the fact that the Uchiha is a clan of fire-jutsu users.

Itachi is relatively popular among many fans of Naruto, often having ranked in the top ten in Shonen Jump magazine's popularity polls since his introduction. He was first ranked in the third character popularity poll ranked in 11th place. He was ranked 9th place during the fourth popularity poll, and 6th place in the fifth popularity poll. During the sixth, most recent popularity poll, he again was ranked in 11th place.

Background


A genius above all others, Itachi was born into the Uchiha clan and praised by all as the best of his generation. However, not even his family, friends, or teachers could understand him.

Not much is known about Itachi's childhood except that when he was only 4, Itachi had already witnessed countless lives lost due to war, which emotionally traumatized him and made him into a pacifist. It is also known that at age 7 he graduated from the Ninja Academy after only one year at the top of his class. He also graduated from the Academy and mastered the Sharingan at age 8, passing the Chunin Exams at age 10 and becoming ANBU Captain at age 13. According to Madara, Itachi also had a lover, whom he killed during the Uchiha clan massacre.

He was praised highly by his father, who saw the family's future in Itachi and neglected his other son - Itachi's little brother, Sasuke. However, during this time Itachi showed great affection towards his little brother, Sasuke, and even encouraged his father to come to the Academy when Sasuke was enrolled, something their dad had otherwise forgotten, by saying that he would otherwise not come on a mission.

After being asked to spy on his clan by the village elders he started acting strange, not coming to the clan meetings and refusing to train with Sasuke. The village elders, finally sure of the Uchiha's plans to take over the village, ordered Itachi to eliminate everyone in his clan. With the help of Madara's teachings (and possibly the help from Madara himself), he slaughtered his entire clan overnight (with the exception of Sasuke). Due to the fact that Sasuke was never to know about the Uchiha's attempt at a coup d'etat and the Konoha higher ups's orders, and the fact that Sasuke's life was worth more than the village to Itachi. Itachi used his Mangekyo Sharingan to capture Sasuke in a Genjutsu and show him how he had killed everyone. After this Sasuke ran away, but Itachi confronted him again and explained that he did it all to test himself. He also explained that the new eyes he had acquired could also be acquired by Sasuke and all he had to do was to kill his best friend. Telling Sasuke that he let him live because he had the potential to become as strong as him, he also tells him to hate him and detest him, if he ever wanted a chance of defeating him.

Personality
Ever since his first appearance, Itachi had always been mysterious and had acted as though he was hiding his true self. While flashbacks to his past show that he was a compassionate brother and person, his later acts and claims made it seem that this was mostly just an act. But, surprisingly, he actually was the compassionate brother he once claimed to be, but he hid this to protect Sasuke.

As a member of Akatsuki, he possessed incredible self control of his emotions. He constantly displayed an emotionless personality, though at times, he appeared to have a slight degree of anger or frustration on his face. He only showed surprise when opponents proved more powerful or skilled than he had expected, and even then he didn't lose his composure. He did not possess any arrogance, and fully justified any statements he made about his power, and even complimented his opponents at times on their abilities.

In addition to being an extremely powerful ninja, Itachi had also shown equally impressive intelligence. He was shown to be extremely mature and wise for his age. He was a very keen minded individual as shown from how adept he was at thinking things through. He was exceedingly sharp and observant to any situation at hand as he was rarely surprised or caught off guard and also displayed great intuition he is almost never deceived and even then almost instantly realizes the truth. In addition, he had also shown to have great deduction and analytical skills from how quickly he could determine his opponent's tactics and effectively counter them. Despite his status as a wanted criminal and having murdered a significant portion of his family, Itachi had no enjoyment of violence or combat, instead preferring to avoid battle or, if this is not possible, end it as quickly as he can.

Itachi's only initial interest was in Akatsuki's goals and his only loyalty appeared to be to the organization and its members, putting the organization's success and secrecy before everything else. As such, Itachi got along with his partner, Kisame, much better than most other Akatsuki members do with their own partners. Kisame appeared to have a deep loyalty to Itachi, immediately doing as he instructed and constantly looking out for his well-being. Itachi treated all of his fellow Akatsuki members to this same, more respectful personality, although his courtesy was rarely returned by the other members.

However, when he was in a Genjutsu duel during his fight with Sasuke, he aggressively and violently claimed he only let Sasuke live so he could take Sasuke's eyes and obtain his own Eternal Mangekyo Sharingan, and then he claimed the Uchiha clan was nothing but tainted and evil since many members would kill their friends to gain the Mangekyo Sharingan, and take another Uchiha's eyes to make its power permanent. Once the Genjutsu was released, he called it his true self, implying his calm, emotionless personality was also a facade.

Madara, however, later revealed that this was not the truth. Itachi really was the brother that he once claimed to be only an act. He had killed his clan only because he had been ordered to by Konoha to stop the Uchiha from rebelling against the village or else Konoha would have been destroyed if a clan as strong as the Uchiha rebelled. His childhood experience in war had caused him to greatly fear and detest the violence the Uchiha could cause, so he made the incredible sacrifice, and decided to murder his entire family, creating the image of his "evil" side that so many had known him to be. Deep down, Itachi had cared a lot for Sasuke, so he never revealed the treachery of the Uchiha clan to keep his brother believing their clan was a noble one. Itachi had always planned to die by Sasuke's hands, so he could compensate for all he had done by making Sasuke's name known as the hero who defeated the one who slaughtered the Uchiha clan. The reason why Itachi didn't kill Sasuke was because he loved Sasuke more than anything else.

Appearance
It has been said by many that Itachi and Sasuke have a similar appearance. Itachi, like his brother, had long black hair in a lighter shade and similar style, but without the spiky style in the back. He also had a long ponytail in the back of his hair (that he obscured with his Akatsuki cloak after joining the organization). His skin was also slightly darker. He, like all members of his clan, possessed dark grey eyes. Itachi's most distinguishing characteristic were his long pronounced nose ridges under his eyes (which he inherited from his father Fugaku). They also appeared longer in the manga than in the anime. Itachi actually looked more like his father, while Sasuke looked more like his mother Mikoto. He was fairly tall, but slightly shorter than Kakashi.

When he lived in Konoha, his casual clothes would consist of a black shirt with a large Uchiha Clan symbol on the back of it, and black pants with a weapon's pouch strapped to them. Whenever on duty, he would wear the traditional ANBU uniform, but he was never shown wearing a mask. As a member of Akatsuki, he wore the traditional Akatsuki cloak, and he usually kept the center of it buttoned down. After his cloak was incinerated by Sasuke's Kirin during their fight in Part II, it was revealed that he still wore his casual clothes underneath that. Like almost all members of Akatsuki, he wore the headband of his home village, Konoha, with a mark through it to symbolize his broken ties with the village (though he actually was still fighting for Konoha).

Return of Itachi arc
Itachi was first introduced alongside Kisame during a mission to kidnap Naruto Uzumaki, commenting about the damage done to Konoha by Orochimaru's invasion. (Tobi later claimed that he went back to warn The Elders and Danzo about not harming Sasuke as the Third Hokage had died). When Kisame responded by asking Itachi if he still had any feelings left for his village, Itachi claimed he had none left at all. The two, before searching for Naruto, quickly stopped for tea due to a suggestion by Kisame. While there, however, their uncommon clothes drew the attention of Kakashi Hatake, who had Asuma Sarutobi and Kurenai Yuhi follow Itachi and Kisame. Itachi and Kisame nearly managed to escape Konoha, though Asuma and Kurenai caught up to them in time.

After the two revealed their identities, Itachi and Kisame were quick to battle Asuma and Kurenai after they refused to leave unharmed. Despite their high ranks of Jonin, Asuma and Kurenai stood little chance to the two Akatsuki members. However, the arrival of Kakashi, who had gotten worried, managed to keep Asuma and Kurenai from receiving any major damage. After a short skirmish with Kakashi, Itachi activated his Mangekyo Sharingan, and used one of its Genjutsu, Tsukiyomi, which managed to put Kakashi in bed for many days. After Kakashi revealed he had knowledge of Akatsuki, Itachi ordered Kisame to kidnap Kakashi and kill Asuma and Kurenai, up until Might Guy shows up, revealing that he's already told the ANBU about the two Akatsuki members. Itachi and Kisame retreat, saying they don't want to start a war.

Itachi and Kisame then continued searching for Naruto, though trouble arose when Jiraiya took Naruto to search for Tsunade. While at first they worried about the possibility of having to battle Jiraiya, Itachi used a Genjutsu on a pretty woman to seduce Jiraiya into leaving Naruto alone in a hotel. Taking the chance, Itachi and Kisame confronted Naruto, though at the very same moment Sasuke Uchiha, Itachi's younger brother, immediately arrived to defend Naruto and seek revenge on his brother. Itachi handled his brother with ease while Kisame and Naruto watched, though Jiraiya arrived in time to save the two boys, having not fallen for the hypnotized woman's charm since he knew that pretty women did not usually act that way toward him.

Jiraiya immediately asked Itachi and Kisame if their real goal is kidnapping Naruto, to which they agreed with and Itachi understood that Jiraiya was the one who told Kakashi about the Akatsuki. Though Jiraiya wished to fight them himself and prevent others from getting hurt, he honored Sasuke's feelings and allowed him to fight Itachi. Itachi, however, only proved Jiraiya wrong to let Sasuke fight by using his Mangekyo Sharingan on his younger brother to land the finishing blow(most likely to re-empower Sasuke's hatred for Itachi because Itachi noticed began to give up hope for killing Itachi, Itachi used Mangekyo Sharingan to make Sasuke relive the Uchiha massacre for 24 hours). Jiraiya barely saved Sasuke in time by using the Toad Mouth Trap, which transformed the entire hotel hallway into a toad's belly to trap Itachi and Kisame. Despite Jiraiya's claim that no one has fled this technique before, the two Akatsuki partners escape with Itachi's Amaterasu, leaving him exhausted.

Sasuke Retrieval arc
While not making a physical appearance in this arc, Itachi did appear in the form of a hologram during a meeting in Akatsuki's Land of the River headquarters. When asked by Sasori about Sasuke, Itachi remained silent, though Deidara interrupted by telling the two not to worry about Sasuke.

Rescue Gaara arc
Itachi made his Part II introduction as a clone created by Pain using the body of Yura to distract Naruto, Kakashi, Sakura, and Chiyo, who attempted to rescue Gaara. The clone fought the team with combinations of Genjutsu and Ninjutsu. Kakashi, however, used a shadow clone to bind Itachi long enough for Naruto to use his Oodama Rasengan, eventually killing the clone. The scene then changed again to see Itachi and Kisame sitting on a mountain, explaining of the double-body clone that they had to use a third of their chakra. They then went back to Akatsuki

Hunt for Itachi arc
Following Kisame's capture of the Four-Tailed Beast, Itachi and Kisame had a conversation about the Tailed Beasts. During the proceeding meeting to seal the Four-Tailed beast, Itachi and Kisame told by Pain that Sasuke started a team with some of Orochimaru's former agents to kill Itachi.

After the death of Deidara, Itachi and Kisame were told by Zetsu that Sasuke died by Deidara's finishing blast, along with Deidara himself and Tobi. Afterward, as he walked under the strange rain that lasted for days, Itachi looked up, and Kisame mentioned that it was "weird" how Itachi seemed as if he were crying. Then, Kisame said it was a shame what happened to his partner's little brother and Itachi became the only survivor of the Uchiha clan. And as he continued to look up, Itachi said in response to his partner: "No, he is still alive, and besides..." before he finished, the sky became clear.

Itachi later chose to send a clone to visit Naruto, who was hunting Sasuke. Though he claimed he wished only to talk, Itachi was forced to stop Naruto's attacks. Whether or not Itachi managed to tell Naruto what he wanted was unknown, as after this the chapter showed the progress of Sasuke. Itachi's clone then left while another visited Sasuke, claiming to want to have a final battle between the two. Sasuke fought Itachi's clone, and it told Sasuke of where they were to have their actual final confrontation, which was in an Uchiha Hideout nearby. However, in chapter 403 it was revealed that Itachi questioned Naruto on his dedication to both Konoha and Sasuke and, when Naruto gave him the answer he wanted to hear, apparently gave him a portion of his power, commenting that he hoped that Naruto would never have to use them, then left to go to Sasuke.

When Sasuke finally arrived, Itachi asked Sasuke what his Sharingan could see, to which Sasuke responded he saw Itachi's death.

They then had a short hand-to-hand fight, until Sasuke impaled Itachi, at which point another Itachi was seen sitting back on the throne and thus revealed Sasuke was battling a genjutsu. Sasuke then appeared behind stabbing Itachi to reveal he too casted a genjutsu. He then asked who the third Uchiha survivor was. Itachi claimed the Uchiha to be Madara Uchiha, and told Madara's story. He revealed the "Eternal" Mangekyo Sharingan can give a user immortality, but the user must take the Mangekyo Sharingan eyes of his or her sibling of the same clan, the Uchiha, referring Sasuke as his "spare" set of eyes. From Zetsu's perspective it was revealed that the entire battle and conversations up until this point have all been a Sharingan Genjutsu battle, and neither Itachi or Sasuke had moved once.

The two began another fight which ended with Itachi catching Sasuke in Tsukuyomi and appeared to have taken his eyes. Sasuke however, and much to Zetsu's surprise, managed to break free from Tsukuyomi. Leading Sasuke to believe there was no further point in using Genjutsu the 'real' battle began. Itachi followed up with using Amaterasu, but Sasuke shielded himself by shedding his skin, a technique he was able to use while Orochimaru was sealed within him. Sasuke then used his trump card, Kirin, on Itachi. However, Itachi survived by using Susanoo to defend himself. At this point, his usage of the Mangekyo Sharingan techniques had caused him to go blind.

As Sasuke's chakra had been exhausted, Orochimaru was then set free, only to be impaled by Susanoo's Totsuka sword, trapping him in a permanent Genjutsu. After this, Itachi went up to Sasuke, raising his hand as if he were going to take his eyes, but he poked Sasuke in the forehead instead saying his last words, after which he collapsed and died. Zetsu remarked that Itachi must have been injured before the fight began, as Itachi was not able to dodge attacks he normally could and wasn't fighting at full power. Itachi couldn't dodge the attacks because he was being killed from the inside by a deadly - and as of yet unknown - virus. Itachi's dying words as he poked Sasuke in the forehead were "I'm sorry Sasuke. There won't be a next time.", which was a reference to the times when he poked Sasuke's forehead when they were children after the latter asked him to train him.

It is later revealed that Itachi never had any intent on taking Sasuke's life, but was actually trying to push him to his limits so that he could free him from Orochimaru and his Cursed Seal and have Sasuke activate his Mangekyo Sharingan.

Post-Death
After Sasuke collapsed, Zetsu left for the battle between Naruto's Team and Tobi; and, after being asked, informed them that Itachi had died and Sasuke was probably on the verge of dying as well. Tobi and Zetsu then left to gather Sasuke and Itachi's corpse to an unknown location. There, Tobi was then shown trying to talk to Sasuke, but he was unresponsive. Tobi then revealed he is also a living Uchiha and the man who knows the "truth" about Itachi Uchiha. When Sasuke saw Madara's Sharingan Eye, the Mangekyo Sharingan was suddenly awakened in his left eye, attacking Madara with Amaterasu. Somehow, Madara managed to survive the attack, even though he was completely engulfed in the searing flames of the eye technique. Recovering, Madara suggested that Itachi transferred his eye techniques to Sasuke for protection, by killing Madara. He continued his speculation, saying that he set it up so that the Amaterasu would activate at the sight of his Sharingan.

After Sasuke asked why, Madara continues by saying it was to protect Sasuke. During this time Madara also revealed that it was him who helped Itachi on "that night" and persuaded Sasuke to inquire about Itachi by telling him that Itachi did everything he did, because he wanted to protect the Shinobi World, Konoha, and most importantly, his little brother, Sasuke.

He continued on by telling Sasuke to remember his "kind brother", Sasuke reminisced about Itachi, then fainted. When he awakened, he had been tied up by Madara so that he didn't leave. Madara went on saying that the only people who knew the truth about Itachi were the Third Hokage, his two advisors Homura and Koharu, and Danzo. He stated that Itachi massacred the Uchiha clan and left Konoha, were all on orders from Konoha. He continued saying that Itachi "killed his sense of self" to carry out the mission. Sasuke, now confused asks "Why?". Madara, in turn, told Sasuke that he must start from the very beginning of Konoha's foundation in order to reveal Itachi's truth.

Madara revealed that before Konoha came to being, there had always been competition and battles between the two greatest shinobi clans: the Senju clan and the Uchiha clan. However, the Senju offered a peace treaty that was signed between the two clans. Madara suspected that the Senju clan would never keep their word and eventually wipe out the Uchiha clan. After the Fire Country was established, Madara was furious that Hashirama Senju was named the First Hokage and wished to challenge him and the Senju clan for control over the Konoha. However, no one from the Uchiha clan agreed with him, believing he was being power-hungry. They turned their backs to him. Filled with hatred, Madara left the country. In an act of revenge Madara summoned the Nine-Tailed Demon Fox and attacked Konoha. While Madara was defeated by the First Hokage and presumed dead, the Nine-Tails was defeated for this time. The incident caused many in the village to mistrust the Uchiha clan as a whole. When the Nine-Tailed Demon Fox attacked Konoha a second time, the upper echelon suspected the Uchiha clan was behind the attack since their Sharingan can control the fox demon. Some of the members from the Uchiha clan became rebellious upon knowing that suspicion and formed a coup d'etat against Konoha. In response to that, Konoha stationed a spy amongst the group: Itachi. Because of this, the manga stated that it was "The beginning of Itachi's hell."

Itachi had been four years old during the Third Shinobi War. Due to the tragedies he had witnessed, he became a pacifist and put the stability of the village above all else. Itachi loved the village and had no interest in clan politics. However, he was ordered by his father to enter ANBU as a spy for the Uchiha. Itachi realized that if a clan as powerful as the Uchiha instigated a rebellion, the entire Land of Fire would feel its effects, weakening the nation. Such a trauma would have undoubtedly been seen as an opportunity for attack by the other nations, thus starting a Fourth Shinobi War. To circumvent such a disaster, Itachi betrayed the Uchiha, becoming a double agent for the village. Although the Third Hokage made attempts to negotiate with the clan, the Uchiha continued to plan their "secret" coup d'etat. The elders of Konoha thus ordered Itachi to covertly eliminate every Uchiha and leave the village forever. At this time Itachi approached Madara, who at the time was seeking revenge on both the Uchiha and the Senju Clans. In return for the safety of the village, Itachi offered to help Madara slay the Uchiha Clan. Itachi performed his mission, but when the time came, Itachi was unable to overcome his love for his little brother, Sasuke. As a result, he told his brother he had slain the clan merely to test his abilities, and gave Sasuke the goal of revenge in order to make Sasuke stronger. In order to ensure Sasuke would not live in shame because of his heritage, Itachi implanted the idea in Sasuke that the Uchiha clan were noble members of Konohagakure and that he had killed them for petty reasons. Itachi begged the Third Hokage not to tell Sasuke the truth and to protect him from the elders. Itachi also threatened Danzo that he would reveal Konoha's secrets to other villages should he harm Sasuke. After his last mission for the village was completed, Itachi spent the next several years keeping an eye on the Akatsuki from the inside, and planning his own death at Sasuke's hands.

After the Third Hokage's death, Madara explained that Itachi came to the village in order to warn Danzo and the two elders that he was "still alive". Also, he planned his whole fight with Sasuke to awaken his brother's Mangekyo, to remove Orochimaru's Cursed Seal, and to die in front of him, which was Itachi's life goal and final mission. It was revealed that Itachi wanted to die by Sasuke's hand so that he would become a hero for avenging the Uchiha Clan. He entrusted the Uchiha name to Sasuke, hoping he would rebuild the clan on a new foundation of honor and nobility. During the fight Itachi was plagued by an illness that would've killed him earlier had it not been for medicine and his love for Sasuke. For the sake of Konoha and for Sasuke he was willing to die as a traitor and criminal. He traded honor for disgrace and Sasuke's love for his hatred, and even then he died smiling. In a flashback, it was revealed that Itachi, despite his love for his brother, he didn't truly know what Sasuke would do next. Through a genjutsu, Itachi gave some of his "power" to Naruto as a fail-safe (what the power is, remains unknown) in case Sasuke should attack Konoha.

Abilities
Since a young age, Itachi's intellect and talent have shown their brilliance in everything he did as even his teachers said his progress hardly required any help. In the few battles he had been seen in since the start of the series, Itachi was shown to be an incredibly powerful ninja, and easily one of the strongest shinobi in Naruto, as demonstrated by his ability to easily defeat Deidara and Kakashi Hatake, as well as having his skill praised by several people including Madara Uchiha and Orochimaru, two of the strongest ninja in Naruto. By the time he was 13, he was already the most powerful living ninja in the Uchiha Clan. Even when battling with a clone that had about thirty percent of his power, his skills allowed him to still fight evenly against Kakashi and assistance from Naruto in Part II. He has demonstrated tremendous skill in all 3 forms of ninja combat. He was a master of all the Uchiha clan's techniques and the Sharingan, as he had demonstrated great talent with its abilities, such as its unique Genjutsu throughout the series. When faced with an opponent's Genjutsu, Itachi could use his Sharingan to dispel it or perform Demonic Illusion: Mirror Heaven and Earth Change and turn the Genjutsu against its user. Itachi was also noted to be very fast, both in his ability to maneuver and accelerate (when fighting Kurenai and Kakashi) along with his movements such as hand seals. Kakashi, an elite Jonin-Level ninja and fellow user of the Sharingan, had great difficulty keeping up with his speed as he couldn't properly see Itachi form any hand sign's when he performed a jutsu. Sasuke later commented on this speed in Part II during his fight with Itachi, since Itachi was capable of forming hand seals without them being noticed by Sasuke, while he was throwing multiple shuriken and defending Sasuke's attacks at the same time. Itachi's combat style usually revolved around indirect attacks and deceptions, fitting his pacifist nature. According to Sasuke, Itachi's tactics usually envolved the usage of crows, either created from a clone or genjutsu.

Itachi also possessed the Mangekyo Sharingan, which increased his already great power, and enabled him to use his most powerful techniques. With his left eye, he could use Tsukuyomi, a Genjutsu that traps an opponent's mind in an illusionary world, torturing them for what seems like days in a matter of seconds. With his right eye he could use Amaterasu, a Ninjutsu which allowed him to create a black flame that he can direct with his eyesight to burn through seemingly anything in its path, including fire itself. His final known technique was Susanoo, a technique that manifested as a spectral being wearing a tengu mask. It wielded the Totsuka Sword, a spectral sword with the ability to seal anything it pierces into the gourd that serves at its hilt, trapping the target in a pleasant genjutsu state forever, and Yata's Mirror, a shield that can reflect any attack. Zetsu, a fellow Akatsuki member, stated that Itachi's mastery of the Sharingan's Eye Techniques combined with the legendary weapons of Susanoo made him invincible.

Despite his mastery of the Mangekyo Sharingan, Itachi suffered greatly from its side effects. His eyesight would worsen after every activation of the Mangekyo and he would eventually go blind from its power, with his Sharingan forever sealed away. Itachi was so close to blindness that by the time he activated Susanoo in his final fight, both Sharingan eyes had gone completely blind and turned white. Itachi also suffered from an unknown sickness. This disease required him to take all kinds of medicines to prolong his life. Multiple use of the Mangekyo in a single battle would extremely weaken his physical body and caused internal bleeding. For Itachi to use Susanoo, a summoning which drains the life energy of its medium, for even a short period, would surely lead to his death.

In terms of standard Ninjutsu, Itachi could create shadow clones to perform techniques for him and act as shields from attacks. These clones could also be commanded to explode with Clone Great Explosion. As a member of the Uchiha clan, he could also perform "Fire Release: Great Fireball Technique" to catch opponents in a blast of fire, and in the anime could breathe multiple fireballs with Fire Release: Phoenix Immortal Fire Technique. With Water Release: Water Fang Bullet he could also catch targets in a circle of crushing water.

Trivia

 * Itachi's primary use of genjutsu could possibly stem from his pacifism, as genjutsu only creates illusions, rather than physically harming the target.
 * Itachi rarely ever kills anyone(Except for the genocide of his entire clan), most of the people he fights end up in hospital (See Kakashi).
 * According to Pain, Itachi's reason for fighting is "ideology"
 * Throughout the series Itachi's true power is never fully shown.

Quotes

 * "Why is it that the Uchiha clan was known by all and feared by all? I'll show you what the Sharingan can do when it's wielded by a true heir of the bloodline."
 * "You are not even worth killing."
 * "Being the best isn't all it's cracked up to be. When you have power, you become arrogant and isolated from the world, no matter how coveted and sought after you are in the beginning."
 * "I've lost all hope for this pathetic clan."
 * "You are weak. Why are you weak? Because....., you lack hatred."
 * "Foolish little brother, if you wish to kill me, hate me, detest me, and survive in an unsightly way. Run, run and cling to life. And one day, when you have the same eyes I do, come before me."
 * "People live their lives bound by what they accept as correct and true. That's how they define "Reality." But what does it mean to be "correct" or "true"? Merely vague concepts... their "reality" may all be a mirage. Can we consider them to simply be living in their own world, shaped by their beliefs?"
 * "We are brothers. That is a unique bond. I am the barrier you must overcome, so you and I will continue to exist together, even if you hate me. That's what being a big brother means."
 * (Last Words, to Sasuke) "I'm sorry Sasuke. This is the last time"

Reception
Itachi has ranked highly in the Shonen Jump popularity polls for the series, continuously placing in the top ten and reaching sixth place once. There has not been another poll as of 2005.