Oronis
Oronis was born Keltis, and served as one of Rajaat's Champions during the Cleansing War. After the Champions rebelled, he became sorcerer-king of Kurn, to the north of the Tablelands. Eventually, he came to regret his past as a defiler and his genocide against the lizard men, and swore to act as a force for good on Athas. He was the first sorcerer-king to manage to turn back from the transformation to a dragon, and even managed to become an avangion.
He created the city of New Kurn hidden in an idyllic valley, and started moving his subjects there, leaving only enough in Kurn to make it appear to be a normal city. This was made easier by the very weak trade links that Kurn had with other cities.
The valley of New Kurn is possibly the closest place on Athas to the Green Age. Oronis has sworn to return the entire planet to this state, and works with druids and the Veiled Alliance whenever he can without revealing himself to the other sorcerer-kings.