The greatest works of Zircon of Minoc, the Mystic Weapons were first found by the Stranger and Companions, after all eight Shrines gave the Stranger partial Avatarhood. Following several clues, they were able to eventually learn their location from Lady Tessa. These special swords were found in Serpent's Hold, in a secret place under the training hall. With the help of these weapons, they managed to finish off the foes that blocked their way in the Abyss.
Thought lost after this, the Avatar found them again in the Underworld in Ultima V, in a lava pool under the Abyss, near the dungeon Hythloth. These weapons again proved their worth, taking down the foes in dungeon Doom.
It is unknown what happened to them after this.