The Revolving Blade Sword (廻転刃刀, Katen Yaibatou) is a superheated rotating blade capable of slashing through the metal of most knightmares. The sword is constructed similarly to a chainsaw, wherein small blades (also known as teeth) circulate around the length of the blade; the main difference is that heat is used to further the effectiveness of the sword, making it even sharper. However, it appears that the Revolving Blade Sword is ineffective on heavily armored knightmares such as the Mordred which withstood a direct hit from it without a scratch. There is a Britannian equivalent to the Revolving Blade Sword that predates the Japanese model, called a Maser Vibration Sword.
Revolving Blade Swords were originally used only by the Four Holy Swords and Kyoshiro Tohdoh equipped to their Gekka, but later became standard equipment for all The Black Knights' commanders for their Akatsuki Command Model Zikisan. However, Tohdoh abandoned the Revolving Blade Sword in favor of a variant known as the "Brake Sword" and has only been used by his personal knightmares: Kyoshiro Tohdoh's Gekka and the Zangetsu. The Brake Sword is similar to a Revolving Blade Sword, but differs as it has thrusters to allow the changing of its movements or Tohdoh's knightmare itself. It also has a single Slash Harken attached to its pommel. There are also simplified versions which unfold and are shaped more like batons with a blade extending from the top, which was used by the standard knightmare of the Black Knights, the Akatsuki.