Gwydion is the true name of the Magician, the personification of one of the Major Arcana. He typically appears in the form of an anthropomorphic fox.
In life, he was a powerful Zantine sorcerer descended from King Durin. Unsatisfied with the real world, he used his powers to create the Arcane Realm. Made out of his magic, the Realm lacked the inner logic of reality, and as a result Gwydion eventually became trapped within his own creation. Upon his death, his spirit was unable to move on, remaining imprisoned within the Realm.
Lonely in the cage of his own making, Gwydion successfully lured a few of his relatives into the Realm, trapping their spirits there upon their deaths. In total, he brought twenty people in; they each became the Arcana. But his plan to collect companions backfired, as the Arcana soon began to fight amongst themselves.
To stop the warfare, Gwydion convinced them to concentrate their efforts on penetrating into reality. They developed a series of elaborate plans to do this, the details of which are not yet known. It is known that they have taken a liking for making deals with mortals.
The Magician's sphere is magic, illusions, and deceit. Thus, Gwydion tends to prey on magic users and people who want to appear to be something they are not.