Yama-Kowasu Ryū Akuma

Yama-Kowasu Ryū Akuma ( "Ryū Akuma" | 山 壊す リュウ鬼, Literally meaning: Mountain-Breaking Dragon Demon ) is a large sentient sword, comparable in size to the Kubikiribōchō. It is described as the most terrifying sword in all of existence, and has even earned titles such as "The Devil's Manifestation" and "Hell Incarnate" (地獄の化身, Jigoku Keshin), further adding to its fearsome reputation. Like Samehada, Ryū Akuma's construction is atypical in that its actual blade is comprised from a series of downward-facing dragon scales running along the entirety of it's length until it's hilt, at the base of which is a small skull. The more that Ryū Akuma is swung, the stronger it becomes, absorbing ambient chakra in the air in order to produce infinite flames, it's scales to become so long that they ultimately resemble dragon skin and its mouth, located at on both faces of the blade, to become even more pronounced. Unlike Samehada, Ryū Akuma cannot be wrapped, as it's very presence is a constant danger to everything around it, as so it must be summoned by it's user.