C0

The highest form of the Iwagakure Kinjutsu's explosive clay (it's ), C0 is a suicide-bomb technique used as a last resort. The user reveals a mouth on their chest, which is stitched up. After undoing the stitches, the user feeds it a large ball of clay. The mouth on their chest has a direct connection to the user's heart, so a large amount of chakra is built up. It then kneads chakra directly from the meridians of the heart and keeps doing it without interruption until the moment of the explosion. The user's explosive chakra then manifests itself in their veins, flowing through the body. These "veins" then condense into a sphere that slowly cracks open and detonates, producing a unique explosion that covers a ten kilometer blast radius.

Trivia

 * The shape of the explosion bears a resemblance to Tarō Okamoto's Tower of the Sun.