Izanagi

Izanagi is a genjutsu that's meant to be cast on oneself instead of others, and it's the most powerful among them. When activated, the caster removes the boundaries between reality and illusion within their personal space. To a degree, this allows the user to control their own state of existence. It is normally only active for the briefest of moments.

When Izanagi is activated, it is capable of turning injuries and even death inflicted upon the user into mere illusions. Whenever the user receives a fatal injury, he or she automatically fades away as a genjutsu, and then returns back to reality, physically real and unscathed. The Sage of the Six Paths' use of Izanagi was not limited to avoiding death; with it he split the chakra of the Ten-Tails into the nine tailed beasts. The process he used is explained to have initially involved the administration of imagination, and the spiritual energy which forms the basis of Yin chakra to create shape and form from nothingness. Then, through the application of vitality, and the physical energy which forms the basis of Yang chakra, he would breathe life into the prior form. Thus, a technique with the power to turn imagination into reality was born, known as Izanagi.

Izanagi can only be used by those with the genetic traits of the Sage of the Six Paths. The Uchiha, descended from the Sage, are able to perform Izanagi with their Sharingan. In exchange for the brief control of reality that it allows them, the Sharingan with which Izanagi is used becomes blind. For this reason the Uchiha labeled it a kinjutsu. Danzō Shimura, in an effort to make practical use of the jutsu, had ten Sharingan eyes embedded onto his right arm. He also had Orochimaru extend the lifespan of each Sharingan's Izanagi to a minute, allowing him to use the technique for up to ten minutes, with breaks in between as he deemed necessary. However, because Danzō's not an Uchiha, his chakra levels drop substantially every time a new Sharingan begins to use it.

To make full use of Izanagi, users must also have the genetic traits of the Senju, who are also descended from the Sage. For this reason Danzō had some of Hashirama Senju's DNA transplanted into his arm, which had the added benefit of increasing his energy levels. Madara Uchiha also makes use of Hashirama's DNA, though he claims to have gained control of it, unlike Danzō. Perhaps because of this reason, Madara is able to sustain Izanagi for five to ten minutes while losing only one Sharingan.

Although the Sage of the Six Paths created this technique, it is unknown if he suffered the same drawback of blindness or if his Rinnegan somehow allowed him to escape this drawback.

Influence
Like the various jutsu used with the Sharingan, this jutsu is named after a Shinto god. In this case, it is Izanagi, who, together with his sister and wife Izanami, created the islands and other deities of Japan.

One of the most famous stories about Izanagi tells the tale of how he goes into Yomi, the Japanese underworld, to retrieve Izanami after she died giving birth to the Shinto fire god Kagutsuchi. After he fails to retrieve her and leaves Yomi, he washes himself in a stream. As he cleans his left eye, Amaterasu is born, as he cleans his right eye, Tsukuyomi is born, and as he cleans his nose, Susanoo is born.