Root of Calamity (禍根の力, Kakon no Chikara, Literally Meaning: The Power of the Root of Evil) is a special Secret Ninja Art used only by Imu and Murasaki's family.
The Root of Calamity is only used by Imu and Murasaki's family because of their unique constitutions. They are able to focus their mental power into an explosions, making their bodies several times stronger. The Root of Calamity seems to be activated at high emotional states such as extreme anger or distress.
- The origin of this magical power is unknown before it was passed through generation. One possible theory that it was a known "source" that was used by the Yoma (including Fubuki and Rasetsu).