Kamui (Left Eye) - a space-time ninjutsu that uses Obito Uchiha's left Mangekyō Sharingan. This version of the technique works at a distance. The user looks at a target and creates a "barrier space" around it, whose size they set themselves. When they concentrate, everything inside the barrier is pulled toward its center and transported to the Kamui dimension.
Kakashi Hatake, who received this eye, initially experienced difficulties with accuracy: he often missed, and when he did hit, he could not make the barrier large enough to capture the target whole. Over time, he learned to hit flying projectiles, and later was able to teleport the head of the Demonic Statue of the Outer Path. He can also transport only individual parts of the opponent's body, inflicting mortal wounds; there is no way to defend against this, except with the right eye. Later, Kakashi learned to create a barrier around himself in order to teleport just like Obito.
Since Kakashi is not an Uchiha, using Kamui requires a huge expenditure of chakra from him. He needs time to accumulate chakra, and he can use the technique a limited number of times per day (initially three times, later more). Repeated use harms his vision, even causing bleeding from the eyes. When Kakashi receives the Nine-Tails' chakra, he can use Kamui faster, more often, and on larger targets, estimating the boost to be three times greater.
Madara Uchiha, having received the left eye, could use Kamui even while being a jinchūriki of the Ten-Tails, unlike Obito, who in this state could not pass through objects using the right eye.
