The Mage Ring is like any normal ring, except that it can open folds to travel between worlds. After the Mage died, Nerissa took up her ring along with her identity although she didn't really need the ring after she gained her beloved sceptre. When the Seal was taken and she was absorbed into it, the Mage Ring teleported straight to Phobos. He uses the ring to create a giant fold by using the Great Ring. It is uncertain of what becomes of the Mage Ring after Phobos, Nerissa and Cedric are defeated in Z is for Zenith. Presumably it was buried with the Mage or returned to Kandrakar.