For the trade,
wanted a dragon similar in concept to the sun. Like how the sun is there, giving warmth and life, but is also potentially destructive. This is what I came up with. My idea for it: the dragon got caught in a huge geological event, and is forever trapped and frozen, and over time, had mostly petrified, except for his chest, neck and head. In his attempt to escape the event, his wings were trapped in that position, forming a dome, and humans built a city in this area. Its protected by him, but does not receive much direct light. But a crystal has formed in the dragon's chest, reflecting the light and beaming it down into the dome.