This technique allows the user to turn their body into extremely strong metal, making that part invulnerable. This prevents usages of swords and blades against the user as they simply shatter, making their flesh harder than diamond. Also, with conductivity, the user is able to make Lightning Release useless against them by acting as a grounding agent, so long as they are on land. The user can also use this technique to increase the power behind their physical attacks. While the user can cost their whole body, they tend to only coat part of it at a time to maintain maximum speed. The most common place to change is the arms, as it can be used to defend and then to strike with great power.
Adamantine Armor: Burn (金剛鎧・火傷, Kongōkai: Kashō, Literally meaning: Vajra Armor: Burn): The user will add more fire-chakra to the armor, which will result in the metal becoming red-hot with heat. The user can use this to burn foes when they strike the foe with their great force, and burn without directly hitting either.
Vajra, which is "Kongō" (金剛) in Japanese, is a mythical material that is said to be able to cut through any substance, but it itself, cannot be cut.
Adamantine is a mythical metal used by the gods in Greek mythology, often known as one of the strongest materials in Greek myths.