Izanagi

Izanagi is a genjutsu that is cast on the user instead of others and is the most powerful amongst this type of genjutsu. 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.

While the user remains physically real while fighting, this technique is capable of turning injuries and even death inflicted upon them into mere "illusions". Whenever the user receives a fatal injury, he or she automatically fades away as though they were an illusion all along and then returns back to reality; physically real and unscathed. The technique is based on an ability the Sage of the Six Paths had, referred to as. 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 cast becomes blind. For this reason the Uchiha labelled it a kinjutsu. Danzō Shimura, in an effort to make practical use of the technique, had ten Sharingan embedded into 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 is not an Uchiha, his chakra levels drop substantially every time a new Sharingan is used to activate the technique.

To make full use of Izanagi, users must also have the genetic traits of the Senju, who are also descended from the Sage. Partially for this reason Danzō had some of Hashirama Senju's DNA transplanted into his arm, which had the added benefit of increasing his physical energy and vitality as well as access to Wood Release which could be used to subjugate tailed beasts. Tobi also makes use of Hashirama's DNA, though he claims to have gained control of it, unlike Danzō.

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

Trivia

 * In Naruto Shippūden: Ultimate Ninja Storm Generations, Danzō uses this as his ultimate technique, letting his Wood Release go out of control, creating a tree that crushes both himself and the opponent, and activating Izanagi at the last moment to escape harm.