Complex sentence: He tells the woodcutter that he is exiled, but that he shall always be a king, because he holds the Disk of Odin, the sole thing in the world that has but one side.
Split into simpler sentences: He tells the woodcutter that he is exiled, but that he will always be a king because he holds the Disk of Odin. The visitor claims the Disk of Odin is the sole thing in the world that has but one side.