Koshintō

Koshintō is a unique and powerful Mangekyō Sharingan dōjutsu which, similarly to Kamui, creates a unique and specialized form of space-time ninjutsu. It allows the user two very distinct, yet closely associated feats — and. It is the unique ability of Ryun Uchiha's Mangekyō Sharingan.

Overview
Koshintō allows its user to manipulate the boundaries of space-time in such a way that even other space-time ninjutsu fall victim to its power. This technique, when used through the right eye, can seize control of a pre-existing portal in order to stabilize it. Through the left eye, the user can disrupt all other forms of space-time manipulation. He can also combine either eye power with other techniques in order to apply their affects to a broader maneuver.

Right Eye
The right eye contains the power of spacial suspension. By focusing the dōjutsu, Ryun is able to stabilize portals of space-time, allowing for safe travel between dimensions. Against Seireitou, he also managed to prevent him from preforming any space-time ninjutsu while the technique is activated.

Left Eye
The left eye contains the power of temporal disruption. To use it, he must focus chakra into the left Mangekyō, allowing him to completely sync up with and sabotage his target's space–time ninjutsu. This disruption can range from simply delaying an opponent's emergence from a space-time distortion or portal, to completely trapping them within their own technique, to even closing established portals. This method of syncing with other spacial ninjutsu allows him to use his own technique to access the dimensions of others. During his fight with Sigma Uchiha, he could extend this ability, allowing him to feel out and open dimensional tears to other dimensions, though doing so was apparently very taxing.

Both Eyes
When combined, this technique allows Ryun to freeze a small section of space in time. He later used this on a larger scale against Sigma Uchiha, in order to keep the portal between his own dimensions and the dimension of Kamui, thus preventing Sigma from using Kamui.

Influence
refers to the original animism of Jōmon period Japan which is a basis of modern Shinto practices. The search for traces of Koshintō began with Restoration Shinto in the Edo period. Some movements which claim to have discovered this primeval way of thought are Oomoto, Izumo-taishakyo, and Shinrikyō.

Trivia

 * Seireitou Hyūga originally misidentified this technique for two separated techniques. Ryun later reveals, however, that it is in fact a single technique.