Crystal Release

The is a rare and specialised field of elemental ninjutsu that can create crystal as well as manipulate already-existing crystals and crystalline structures. It is seen only in the anime, and its only known user is Guren. Additionally, due to Guren's crystal dragons being shattered by Kakashi's Lightning Cutter and Kiba having mistaken the actual element for an Earth Release technique, it is assumed earth is one of the elements needed to create crystals.

Overview
According to rumours that Tsunade had heard, Crystal Release can crystallise any substance, thus, earth, water, and wood techniques are useless against it. Using crystal ninjutsu, the user can crystallise any physical material and even the moisture in the air around them, turning them into a weapon. In the case of human targets, Crystal Release can solidify its targets down to the cellular level, imprisoning and even killing the victim should the crystal ever be struck, reducing the mass of crystal and the victim down to crystalline dust.

The Crystal Release, though powerful, has two known weaknesses, the first being that it cannot crystallise either raw energy or chakra as they have no physical mass to crystallise, allowing a person with either energy-based techniques, such lightning, fire, wind, or good chakra control to properly counter it. The second weakness of Crystal Release is that it is susceptible to a specific sound wave frequency; because crystal requires a very precise build-up of molecules, the proper sound waves can break down the build-up before the crystal can properly form. Rinji, taking advantage of this weakness, used his bats to counter Guren's Crystal Release.