Prism Release

The Kakuchū Sharingan (角柱写輪眼, Literally meaning "Prism Copy Wheel Eye") is an advanced form of the Soga Clan's Sharingan that has only been activated by a handful of Soga.

Overview
It also grants them access to other powerful techniques. The Kakuchū Sharingan is distinguished from a normal Sharingan by its appearance, which changes the form of the tomoe seal. Unlike the Sharingan, the appearance of the Kakuchū Sharingan differs from user to user.

Like the Mangekyō Sharingan of the Uchiha the Kakuchū Sharingan is acquired through the death of the person closest to the Sharingan user. To obtain the Kakuchū Sharingan, one must feel the emotion of losing a friend or family, as merely killing them or watching them die will not activate it. Like the uchiha, frequent use of the Kakuchū Sharingan deteriorates the user's eyesight and results in blindness.