The mage Gustacio of Moonshade owned the Flux Analyzer, until it was stolen from him by Vasculio, as he later told the Avatar in Ultima VII Part Two. The Avatar needed it to fix the Black Sword, so that it would be useful again and trap the Banes inside the Ether Gem. The Avatar finally found the machine in Skullcrusher, Vasculio's hideout, and used it to repair the Black Sword. After that was done, it lost its usefulness.