Metal Dust Technique

Metal Dust Technique (金塵の術, Kinchiri no Jutsu) is a unique technique developed by the Kinsei Clan in order to use in conjunction with their metal techniques. One of the biggest advantages of this technique is being able to use it with any metal construct. This technique is simply turning metallic structures into dust. That dust is created from metal and can be manipulated by the user. It's considered to be a stronger defense than Gaara's sand considering that metal is much harder than sand. It can be emitted from the user or it can be made from any metal construct by turning it into dust, which would look as if the construct is melting into the said dust. As it's made out of the user's chakra, the dust can be manipulated at a very fast rate. It can move according to the user's wishes and it can serve as an unyielding defense in many situations.

Furthermore, the user can merge the dust in order to make constructs of metal. It was seen that the dust was turned into weaponry such as Kunai, shuriken and senbon. The dust can be turned back into constructs in an instant, giving the user many options in battle in order to defeat their opponent. If the opponent were to breath the dust, it would lead to them suffocating as the metal would enter their lungs along with the user's chakra. Once the dust is inside the lungs, the user can manipulate it in order to kill his opponent. One of the most popular applications of this is creating constructs inside the opponent's lungs in order to kill them. Or turning the dust into liquid causing extreme breathing problems to the target.

Travia

 * It is believed that this technique is related to gold dust considering that gold is a type of metal.