The Mercury Swordbelt is a piece of alien technology with bizarre powers. It allows its wearer to make a weapon immaterial while transferring the powers of the weapon to the user. It also amplifies those powers, turning the wearer into a living super-weapon. For example, if the Swordbelt were used on a six-shooter, the wearer would gain the power to shoot bullets from his fingers with the power and rapidity of an AK-47.
The Swordbelt was introduced to the public in The Last Otter Warrior, where it was being used by a Limifite pirate rat to cement control over all other pirate rats and embolden them to attack humans. Using an ordinary lighter, the pirate captain gained pyrokinetic powers and become a living flamethrower. He was soundly dfeated by the Otter Warriors Oren and Regie Verden and their companion John Saaman the werecat.
Previous to this, the Mercury Swordbelt appeared in an unpiublished poem about the Mieri King, a historic Venusian monarch as the capstone of his twelve treasures.. "...and last, the belt of Mercury does cause all of these things to be as one with that old, wise Mieri King." Although each of the twelve treasures is a piece of alien technology, it is not known where the Swordbelt originated, though it is theorized that it originated on planet Crowithia, a world where everyone has a different superpower, as an aid for the handicapped.
In sequels to The Last Otter Warrior, it is revealed that the Mieri nation was conquored by the Viji. When the Viji warlord discovered that he could not safely usurp the treasures of the Mieri King, he opened a portal to Earth and scattered them on that distant planet, where they were assumed irretrievable. Centuries later, the Mieri King was discovered in stasis and was taken to Earth, where he recovered all twelve treasures, including the Swordbelt.
In Liberutian, the standard language of Venus, the Mercury Swordbelt is called "Heragur Suradspen"
Combined with a Vest of Bule, the belt creates a walk-in storeroom in transdimensional space, the opening of which is in the wearer's torso.