Унері Ґінкаку

Uneri is the holder of the deviant blade Namakura. Togame offers him anything in exchange for Namakura, but his wish of restoring Inaba can't be fulfilled, so he opts to fight Shichika instead. His style, Zerosen, entails cutting with the sword faster than the speed of light. To hasten the process even more, he wounds himself and lets his blood seep into the sheath, negating the friction of the blade on the sheath.