Mangekyō Sharingan

The is a heightened form of Sharingan. The Mangekyo Sharingan is distinguished from a normal Sharingan through its appearance, which changes the form of the tomoe seal. The appearance differs from user to user; Kakashi's and Itachi's both resemble pinwheels, Madara's and his brother's more look like more detailed forms of the basic three-tomoe Sharingan, and Sasuke's looks like a star. Those who have the potential to obtain it must make a great sacrifice in order to obtain it – according to Itachi, they must kill their closest friend. Itachi, Madara, and Izuna apparently do this to obtain the original version, but this is apparently not the only way to unlock it, as Kakashi has noted that everyone he cared about had died long before the start of the series, so how he developed his own variant is unknown. And even though Sasuke didn't kill Itachi, the trauma of losing Itachi (someone close to him) allowed him to unlock his own version. This means that the real way to unlock the Mangekyo Sharingan would be to lose someone close to you, but since Kakashi noted everyone close to him to be dead, it's still unknown how he unlocked his Mangekyo Sharingan. Also, the Mangekyo Sharingan techniques can be transferred to another Sharingan user, as in the case with Sasuke, who was implanted with all of Itachi's eye techniques. The major drawback of the Mangekyo Sharingan is that it slowly begins to destroy the user's eyesight until they become completely blind and permanently lose their Sharingan. The only way to keep your eyesight is to steal the eyes of a sibling, combining the two Sharingan to create the, which prevents blindness and deprivation of the Sharingan.

In the long history of the Uchiha clan, only a few have been able to obtain the Mangekyo Sharingan-- Madara and Izuna Uchiha being the first. At present, there are three people alive who can use the Mangekyo Sharingan: Kakashi (Presumed Deceased), Madara, and Sasuke.

The Mangekyo Sharingan gives a user access to the most powerful and forbidden techniques of the Uchiha Clan. Itachi has demonstrated through his Mangekyo Sharingan mastery over Amaterasu, Susanoo, and Tsukuyomi. Kakashi has used his Mangekyo Sharingan to perform Kamui. Sasuke's Mangeyko Sharingan hasn't displayed any unique abilities aside from Amaterasu. It is implied that with enough training, one can master all of the Mangekyo techniques as Madara did.

Itachi Uchiha
Itachi Uchiha gained the Mangekyo Sharingan by killing his best friend. With the Mangekyo Sharingan, Itachi is able to use at least three of the most powerful jutsu of the Uchiha clan. The first is Tsukuyomi, a powerful Genjutsu. This technique comes out of and puts strain on the left eye. Upon making eye contact with an opponent, Itachi can use Tsukuyomi to transport them to an illusionary world where days amount to a mere moment in reality. Because Itachi is in total control of this world, he can torture an opponent in any way imaginable, leaving them crippled and in a state of mental collapse, though he hasn't gone further than 3 days. The second technique is Amaterasu. This technique puts a strain on the right eye, and causes Itachi's eyes to bleed. Described by Zetsu as the ultimate ninjutsu, it is shown to be capable of burning through almost anything by creating a jet-black flame said to be as hot as the sun and capable of burning for seven days and seven nights.

The last of these techniques is the devastating Susanoo. The technique summons a massive ethereal warrior, which then fights on behalf of Itachi. In the left hand, the warrior wields, a shield that's capable of reflecting several attacks, and in its right, the legendary , also known as the. The Sword of Totsuka, commonly sheathed in a sake jar held by a third hand growing from Susano'o's right forearm, is an ethereal weapon with an enchanted blade capable of sealing anything it pierces in an alternate dimension where they're trapped in an eternal dream-like illusion.

All of these techniques, however, use massive amounts of chakra and also cause ever increasing damage to the user's eyesight. Itachi himself becomes exhausted of using both Tsukuyomi and Amaterasu consecutively and has to deactivate his Sharingan. Soon, he claims that his ulterior motive is to "steal Sasuke's eyes" to awaken his own Eternal Mangekyo Sharingan. During the final battle between Itachi and Sasuke, Zetsu has revealed that the "Left Mangekyo" possesses the Tsukuyomi, while the "Right Mangekyo" possesses the Amaterasu. It is unknown where Susano'o comes from, and if Itachi even needs the Mangekyo Sharingan to make it work, although it is known that he needs to have at least awakened it to use it.

Kakashi Hatake
Kakashi Hatake developed his own version of the Mangekyo Sharingan during the timeskip. Kakashi mastered a technique that creates a localized interdimensional space-time ninjutsu called Kamui, allowing him to target any object and send it to another dimension. The attack requires considerable effort to aim precisely and appears to leave Kakashi's chakra significantly drained; he collapses after using the technique three times even at full strength in a single day (compared to his other original move, Lightning Blade, which he can use four times a day in part I of the series while he appears to be able to use it six times or more a day-as shown in his battle against Kakuzu).

The appearance of the pupil and tomoe in Kakashi's Mangekyo Sharingan differ from that of Itachi's; Kakashi's looks more like a pinwheel. Before this was shown, Itachi thought that one had to kill their best friend to acquire the Mangekyo Sharingan, yet this has been dissproven in both Kakashi's and Sasuke's case; Sasuke didn't kill Naruto, rather the traumatic effect of losing Itachi after discovering he was really trying to protect him caused his Mangekyo Sharingan to activate, while Kakashi stated that everyone he cared for was already dead, and that he had not activated his Mangekyo Sharingan yet. Currently, the cause of his Mangekyo's activation is unknown, but it is safe to assume that he didn't kill his best friend in order to achieve it.

Madara Uchiha


First Mangekyo

Madara Uchiha was actually the first person to wield this dangerous weapon. When he was young, he and his younger brother were the first people to gain the Mangekyo Sharingan. It took the form of a ring with three circular holes in it. He eventually grew blind from overusing it.

Eternal Mangekyo

After he came in possession of his younger brother's eyes (Madara claims the eyes were a sacrifice from his brother for the good of the clan, while Itachi suggests that Madara did steal his brother's eyes), this unlocked the "Eternal" Mangekyo Sharingan, which made Madara the only weilder of it as of date. His Eternal Mangekyo Sharingan in appearance looks identical to Madara's first Mangekyo combined with Izuna's Mangekyo.

It is believed Madara used its power to control the Nine-Tailed Demon Fox and sent it to attack Konoha on one occasion, though he denies this. Regardless, the attack failed because of the Fourth Hokage's sacrifice.

With the Eternal Mangekyo Sharingan, Madara mastered all the secrets and techniques of the Mangekyo Sharingan. In addition, according to Itachi, Madara unlocked a final and ultimate eye technique, which was the reason why Itachi spared his younger brother Sasuke - in the hope of taking Sasuke's eyes to achieve the Eternal Mangekyo Sharingan and gaining the ultimate Mangeyko Sharingan technique. Currently, the only technique that Madara has shown is an unnamed space/time ninjutsu, which makes him nearly invulnerable as most attacks will pass through him.

Due to his claim that he will use the Tailed Beasts to return his eyes to their former glory, his Eternal Mangekyo Sharingan eyes might have become damaged.

Izuna Uchiha
Izuna Uchiha once possessed the Mangekyo Sharingan as well, his took the appearance of three bars stretching out of his pupil. It is said that he developed his around the time his brother Madara did.

Madara later pried these eyes out of his head, thus creating Madara's Eternal Mangekyo, which took the appearance of Madara and Izuna's Mangekyo combined.

Sasuke Uchiha
After Sasuke Uchiha's battle with Itachi, he wakes up in a cave with Madara nearby. Madara removes his mask to reveal his Sharingan, which upon sight triggers the activation of Sasuke's Mangekyo Sharingan (in the form of Itachi's) and the Amaterasu, setting Madara ablaze. However Sasuke seems to have no control of this and quickly clamps his hands over his eyes.

Madara then explains that Itachi probably transferred all of his eye techniques to Sasuke, to protect his little brother, as a fail safe. It should be noted that during the time Sasuke's Mangekyo Sharingan first emerged it was actually Itachi's Mangekyo transferred to him. This Mangekyo Sharingan still required someone close to him to die. Therefore, Itachi, knowing he had a terminal illness, pushed Sasuke to the limit in battle. This allowed Orochimaru to emerge so that Itachi could purge his influence from Sasuke. Then, by dying before his brother's eyes, he could become Sasuke's "sacrifice".

The first time Sasuke is shown with it is when he announces the formation of the new team "Hawk," to crush Konoha. Sasuke's Mangekyo Sharingan takes the appearance of a six-sided star often resembling the atomic model, and unlike other Sharingans, which have a black design and red background, Sasuke's is the first one that is shown to have a red design and a black background. He has shown the ability to use a genjutsu which can "exploit fearful hearts", in this case to extract information from a victim. This genjutsu could possibly be the Tsukuyomi. He can also use Amaterasu, this time against Kirābī, but with his own Mangekyo and with the opposite eye Itachi used it with. He can also put out the Amaterasu flames as seen with Kirābī and Karin when one of Kirābī's burning tentacles hit her.

Sasuke has been shown to suffer the same side effects as Itachi did when he evoked the powers of the Mangekyo Sharingan; strain and bleeding of the eye (though this might have been because Sasuke was in a weakened state at the time due to the injuries he sustained in his fight with Itachi), rapid draining of chakra, and slowly deteriorating eyesight. It can be presumed that he has started to lose his eyesight faster than Itachi, since we didn't see his brother straining to see things after his first uses of the Mangekeyo, though it's possible that Sasuke was still recovering from his fight with Itachi, also Sasuke's first use of the Mangekyo Sharingan was on a cloud-nin and did not strain from it's side effects until he used Amaterasu on the Eight tailed beast and was in a weak state by the time he used Amaterasu.

Speculation
It was originally believed that Sasuke's Mangekyo Sharingan was actually an Eternal Mangekyo Sharingan and a combination of his and Itachi's Sharingan Eyes. This is believed from when Sasuke's Sharingan took the look of Itachi's Mangekyo when his eyes met Madara's, it was later revealed that, when Sasuke was talking to Madara, he wouldn't take Itachi's eyes, meaning that this is Sasuke's natural Mangekyo, and not an Eternal Mangekyo. In addition, Sasuke's vision has become blurred due to the Mangekyo Sharingan's side effects which doesn't happen when an Uchiha obtains the Eternal Mangekyo Sharingan.