Mangekyō Sharingan

The is an advanced form of the Sharingan that has only been activated by a handful of Uchiha when enduring a traumatic enough experience. They are noted to be the.

Overview
A Mangekyō Sharingan is distinguished from a normal Sharingan by its appearance, which changes the form of the tomoe seal. While the exact design differs for each user, they all resemble pinwheels. It is initially awakened by the trauma suffered from witnessing the loss of someone dear, usually their death. Uchiha have historically misunderstood this criteria as the user needing to be responsible for the person's death, and for that reason they developed the practice of killing their closest friends in order to gain the Mangekyō Sharingan. Obito's Mangekyō activated immediately after his trauma, whereas, in Naruto Jinraiden, Sasuke's Mangekyō didn't activate until several weeks afterwards.

The Mangekyō Sharingan retains all of the Sharingan's generic abilities. In addition to that, the Mangekyō grants powerful abilities that differ between each eye, though abilities may be similar in nature; both Sasuke and Itachi have access to Amaterasu's flames, though the extent to which they can use them differ. The abilities of a Mangekyō Sharingan may not be the same for both of a single user's eyes, as Sasuke's left eye can unleash Amaterasu while the right eye can manipulate his flames with Kagutsuchi. Likewise, each eye may not even be limited to just one ability, as at least Itachi's right eye has Amaterasu and Tsukuyomi.

As each eye houses the particular dōjutsu techniques, one can only access them if they currently house the said eye, even if they were the originator of the said technique. Once a user awakens the Mangekyō in both eyes, they are able to perform Susanoo, even without either eye. In addition to the unique techniques, the of Madara's and Sasuke's Mangekyō Sharingan grants them greater fluidity in their movements when fighting. Madara was able to sense this form and later deduced that he and Sasuke must be connected by more than blood.

As with any dōjutsu, Mangekyō Sharingan can be transplanted into non-Uchiha, granting them all its abilities albeit with steeper chakra demands. Unlike the standard Sharingan, a transplanted Mangekyō Sharingan can be freely activated or deactivated by non-Uchiha at will. Abilities of a Mangekyō Sharingan can also be programmed to activate under certain circumstances, either within the user's own eyes or in a target of the user's choosing; this programming remains even after death.

Using them comes with a certain sensation that sensors can feel, although it doesn't show which technique is being prepared. Even for true wielders, usage of the Mangekyō Sharingan's abilities can cause a great strain on the user. It drains a considerable amount of chakra when simply activating and maintaining the advanced dōjutsu, and even more through each technique used. Even more, it can cause considerable damage to their being, leaving the body in agonising pain and causing deterioration to their vision until eventually over-usage leaves them blind. Their vision can be restored by transplanting the eyes of an Uchiha with strong blood ties — ideally a sibling — thus awakening the so-called. Unlike with other transplants, this second evolution will allow the user to retain their original techniques. Although these eyes merge the designs of the two Uchiha's Mangekyō Sharingan, they're still the eyes of the previous owner and thus react to certain techniques that are aimed at the original owner's Mangekyō Sharingan. Also, they no longer suffer any negative side-effects from using them, even reducing chakra-draining to an unnoticeably minimal level. According to Madara, the Eternal Mangekyō Sharingan is proof an Uchiha has continued to push forward despite experiencing great losses.

The Mangekyō Sharingan also grants its user the ability to read and decode the Uchiha Clan's Stone Tablet more than the standard Sharingan, but less than the Rinnegan.

Itachi Uchiha
Itachi Uchiha awakened his Mangekyō Sharingan after witnessing the suicide of his best friend, Shisui Uchiha, shortly before the Uchiha Clan Downfall. With either Mangekyō he could use Tsukuyomi, an extremely powerful genjutsu that distorts the victim's perception of time. With his his right Mangekyō he could use Amaterasu, creating inextinguishable black flames at the user's focal point. Since he awakened both his Mangekyō, he could use Susanoo. Because both Tsukuyomi and Amaterasu used vast amounts of chakra, combined with his terminal illness, multiple use of the Mangekyō's abilities in a short period of time was particularly debilitating for Itachi, such that after using it three times in one day, he was required to deactivate even his normal Sharingan to conserve energy. Sometime after Itachi's death, desiring the power to kill Naruto, Sasuke Uchiha had Itachi's eyes transplanted into him. Years later, the right eye was destroyed by Momoshiki Ōtsutsuki.

Obito Uchiha
Obito Uchiha awakened his Mangekyō Sharingan after the death of Rin Nohara during the Third Shinobi World War; Obito himself only had his right eye at the time, but the event caused his Mangekyō to simultaneously awaken in Kakashi Hatake, who wielded Obito's left eye. Both eyes wielded Kamui, able to teleport targets to and from Kamui's Dimension, though in different manners. The right eye was able to use close-range Kamui, teleporting the user and/or those they're in contact with. By teleporting only parts of their body there, they could in effect seamlessly pass through other matter. The left eye was able to use long-range Kamui, creating a barrier around a target that teleported them, also able to produce an attraction force to draw other targets close enough in. The left eye could also target the user themselves for complete teleporting. During the Fourth Shinobi World War, it was discovered that each eye was impervious to the others' Kamui.

Madara Uchiha stole Kakashi's eye in order to pursue Obito to Kamui's dimension. There, he exchanged the eye for Obito's Rinnegan, returning both eyes to their original owner, who was currently possessed by Black Zetsu. During this brief period, Black Zetsu also gained access to both Sharingan powers. After Obito was freed from Black Zetsu's control, he used them in combination effectively thereafter to retrieve Sasuke from Kaguya Ōtsutsuki's distant dimension. But soon afterwards, both of his eyes are destroyed when he was killed by Kaguya Ōtsutsuki's All-Killing Ash Bones. His spirit briefly returned to the living plane and inhabited Kakashi, manifesting both Mangekyōs with their respective abilities through Kakashi and, by extension, Susanoo.

Madara Uchiha
Madara Uchiha was the first Uchiha to awaken the Mangekyō Sharingan. It's not known what the individual abilities of each of his eyes were, but he was able to use Susanoo. The straight tomoe of his Mangekyō Sharingan granted him fluidity in his movements when fighting. When Madara's over-usage of his Mangekyō during the Warring States Period left him blind, this prompted his brother, Izuna Uchiha, to bequeath Madara his eyes on his deathbed for the sake of preserving the Uchiha, thus granting Madara the Eternal Mangekyō Sharingan.

Towards the end of his life, Madara was able to evolve his eyes into Rinnegan, which he transplanted to Nagato when Nagato was a child without anybody ever knowing. For the Fourth Shinobi World War, Obito wielded Madara's left Rinnegan as wielding both would have been too strenuous. Eventually both eyes found their way back to Madara after he was revived.

Izuna Uchiha
Izuna Uchiha awakened his Mangekyō Sharingan shortly after Madara did. It's not known what the individual abilities of each of his eyes were. Before he died, Izuna entrusted his eyes to Madara in order to restore his vision and thus protect the Uchiha from extinction. Despite Izuna giving the eyes willingly, Madara is popularly believed to have taken the eyes by force.

Sasuke Uchiha
Sasuke Uchiha awakened his Mangekyō Sharingan after witnessing his older brother, Itachi Uchiha die in battle with him and learning the truth behind his actions. With either eye, Sasuke can cast Amaterasu, as well as shape and extinguish them. Because he awakened both of his Mangekyō, he can use Susanoo. The straight tomoe of his Mangekyō Sharingan grant him fluidity in his movements when fighting. Sasuke is initially reluctant to transplant Itachi's eyes and gain the Eternal Mangekyō Sharingan, claiming that his views were different from Itachi's. Later, he decided he needs the increase of strength in order to kill Naruto Uzumaki, along with the severe deterioration of his eyesight from overuse, Sasuke accepted Itachi's eyes transplant.

After acquiring the half of Hagoromo Ōtsutsuki's chakra, Sasuke's left eye evolved further, into a Rinnegan. While Sasuke is evidently unable to deactivate the Rinnegan, it retains access to all the left Mangekyō's abilities. This eye was destroyed by Boruto Uzumaki while being controlled by Momoshiki Ōtsutsuki.

Shisui Uchiha
 Shisui Uchiha awakened his Mangekyō Sharingan after he "allowed his friend and rival to die". With each of his eyes he could use Kotoamatsukami, a powerful genjutsu that manipulates a target's thoughts so perfectly and absolutely that no one completely, including the target, would have the slightest idea that they were being controlled. However, this technique couldn't be used with the same eye again until after a period of time. In the anime, awakening the Mangekyō Sharingan in both eyes allowed him to use Susanoo.

When Shisui attempted to use Kotoamatsukami in order to avert the Uchiha Clan Downfall, his right Mangekyō was stolen by Danzō Shimura, who felt Shisui's plan was futile and wished to protect the village in his own manner. Fearful that Danzō would take his other eye too, Shisui entrusted it to his best friend, Itachi Uchiha, and begged him to use it to save Konoha. Danzō transplants the eye he took into himself and uses it over the years to manipulate others to his way of thinking, using the chakra of Hashirama Senju to reduce its recharge time. Danzō destroyed the eye before his death so that nobody else could have it. Itachi transplanted the eye he was given into a crow that he planned to use to re-ally his brother, Sasuke, with Konoha. He used it on himself instead when he was reincarnated in order to break free of Kabuto Yakushi's control. Itachi incinerates the crow afterwards so that nobody else could have the eye.

Indra Ōtsutsuki
In the manga, Indra Ōtsutsuki was the first user of the Mangekyō Sharingan. The individual abilities of each of his eyes were unknown, except that he was able to use Susanoo. In the anime, he awakened his Mangekyō Sharingan after killing his two followers. With his left eye, he was able to use Hinokagutsuchi to produce black flames.

Shin Uchiha
 This Mangekyō Sharingan form was uniquely shared between multiple (yet connected) individuals. With his right eye, Shin Uchiha was able to telekinetically manipulate any objects after first branding them with a special mark that he placed by direct contact with his hand. Shin's clones, being genetically identical to him, possess the same Mangekyō Sharingan design and with it the same telekinetic powers. A creature also shares the same Mangekyō Sharingan design with Shin.

Fugaku Uchiha
In the anime, Fugaku Uchiha had awakened his Mangekyō Sharingan after witnessing a sacrifice of his dear friend during the Third Shinobi World War. Although not much is known about his Mangekyō, Fugaku was confident it was strong enough to control the Nine-Tails.

Hagoromo Ōtsutsuki
In the anime, Hagoromo awakened this power after risking his brother Hamura's life to save him from Kaguya's control; however, the design of his Mangekyō Sharingan is unknown because his eyes evolved into the Rinnegan at the same time. While the individual techniques his eyes had are unknown, he was able to create a uniquely massive Complete Body — Susanoo, which was roughly the size of the Ten-Tails.

Sarada Uchiha
Sarada Uchiha awakened her Mangekyō Sharingan when Boruto Uzumaki was framed for killing the Seventh Hokage due to Kawaki's wish, crying in fear for Boruto's safety.

Trivia

 * Originally in the anime, Itachi Uchiha was shown using techniques exclusive to the Mangekyō Sharingan without having it active. This is because Kishimoto had not revealed the appearance of the Mangekyō Sharingan in the manga yet. A true form of the Mangekyō Sharingan was first seen, from Itachi, while Sasuke remembered the events leading to the Uchiha Clan Downfall as he fought with Naruto Uzumaki at the Valley of the End.
 * Despite using his Mangekyō extensively for over a decade, Obito never displayed any signs of fatigue or deteriorating eyesight.
 * The manners in which an individual gains the Mangekyō Sharingan are almost parallel to how an Uchiha awakens their regular Sharingan for the first time, since both need intense emotions to awaken them. While the Sharingan simply requires an intense emotion of any kind, the Mangekyō Sharingan requires a person be traumatised.
 * In the manga, Sasuke Uchiha's Mangekyō Sharingan is the only one with an inverted colour scheme, boasting a red design and black irides.
 * If a person is struggling between whether or not to feel saddened by a person's death, they will experience eye irritation, which will either fade as time passes or will eventually awaken the Mangekyō Sharingan, if they end up feeling genuine sadness.
 * In the manga, Indra's Mangekyō Sharingan is revealed to have a swirl design. This was also depicted and adapted to the anime. However, later in the anime, his Mangekyō bears the same design as Sasuke's.
 * Sarada's Mangekyō Sharingan was teased in a piece of artwork released in the first volume of Boruto: Naruto Next Generations, 7 years prior to its debut in the manga.
 * Despite Fugaku's Mangekyō Sharingan being a secret, his design was featured in a book at the Konoha Library.
 * It is hinted that Straight Tomoe Mangekyō Sharingan is connected to Indra as Madara (correctly) speculated he and Sasuke shared some connection beyond blood due to both of them awakening Straight Tomoe Mangekyō Sharingan, even though he wasn't able to pinpoint their precise connection.
 * It is also hinted that being Straight Tomoe do not correlate to Mangekyō Sharingan design and it also exists in the Sharingan stage as well: Madara's original Mangekyō Sharingan did not have a straight design, but Izuna's did and Madara stated only he and Sasuke awakened a "Straight Tomoe Sharingan" rather than "Straight Tomoe Mangekyō Sharingan".
 * Sarada's Mangekyō Sharingan awakened uniquely compared to all those before her, for her fear of losing someone dear to her as opposed to actually losing them.