Well, I definately going to be designing a Prestige Class for Fire called the Reapers of the Flame. Basically, the Fire Realms were in a constant state of destruction and turmoil before the lawful, regimented Azers immigrated to the planet from the Fire Plane. They saw the societies the way they were and realized everybody needs fire. If the dwarves want to forge their metals, they need fire. If the wind nomads want to cook their fresh caught game, they need fire. So through force of arms, they "unionized" fire, bringing the chaotic orcs and humans under their dominion and opening Fire temples in the Earth and Wind realms, and even reluctantly in some of the Water towns. If you want so much as a torch, you have to come to them. If you don't? The Reapers of the Flame will come for you. Basically, I'm going to take the Black Flame Zealot PrC (admittedly sucky as is) and replace it with a divine fire cleric/barbarian cross. The end result will be a raging, flaming assassin/enforcer designed to hunt down anyone who doesn't pay their dues to the Fire Lords. As for the other elements, I'm going to develop a Holy Liberator, Consecrated Harrier or Stormlord variant for the wind realms, basically the second generation for a Windstalker (ranger) to progress into. I still need to figure out the Earth and Water PrCs, but they'll come to me.