The Kokken Sword is an ancient magical weapon created during the Fourth Era by the same mage who created the Senshi Mages. Since then, it has been tied to their history and power, but its use is reserved exclusively for the First Senshi Mage.
The Kokken Sword has a straight, jet-black blade. Just below the guard, the tsuba, which is also matte black, the ideogram senshi, meaning “warrior,” is engraved in gold. The hilt, the tsuka, is long and wrapped in precisely woven blackened cord. Its design resembles that of the shinobi-tō commonly used by ninja warriors and the army of Myoo. It is also indestructible: its black blade cannot be damaged by conventional weapons. When it clashes with an ordinary blade, it can slice clean through it.
The Kokken Sword recognizes Senshi Magic and can be wielded only by those who possess it. If another mage or a person without Senshi Magic attempts to wield it, the sword reacts by violently repelling them.
The most important characteristic of the Kokken Sword is its ability to merge with Senshi Magic and amplify its power. When wielded by the First Senshi Mage, the sword’s energy combines with the mage’s own, vastly enhancing their abilities and making them a nearly unbeatable warrior.
The sword also possesses the power to open magical portals to other locations within the territory and even to other dimensions, allowing the First Senshi Mage to cross vast distances in an instant. To create a portal, the mage need only think of the place they wish to reach and make a downward slash with the sword. A line of light follows the blade’s movement and gradually widens until it becomes a passage to the chosen destination.
The size of the portal can be increased by changing the movement of the sword. In this case, the First Senshi Mage makes an upward slash and then draws the blade horizontally, creating an opening large enough for several people to pass through.
Not all the powers contained within the Kokken Sword are known. Other forms of magic, hidden throughout the Eras, remain sealed within it, but no one knows of their existence.