Earth Release: Earth Spear

With his earth-element mask, Kakuzu can harden his skin to steel-like quality, protecting him from most attacks. Apparently, this technique also enhances his strenght, to the point of knocking down a giant iron door with just one punch. It is, however, easily defeated by a lightning-based ability. While active Kakuzu's skin changes to a darker tone.

Trivia

 * Like the rest of Kakuzu's techniques, the name of this techniques comes from the legendary mecha anime . The name Domu was taken from the Gundam MS-09 . The name was given kanji to create the name of this technique.