Wish Envoy and Curse Carrier (concept sketches)
Every year these two make a pilgrimage to the Fire Sanctuary carrying that which they specialize. They begin on opposite ends of the world, passing through villages of people who may desire their services. When someone wants a letter, Wish Envoy and Curse Carrier employ three tests of the heart to see if that person qualifies for a letter; if so they are granted thus. That person may then imbue the red letter with a desire.