The Rain Children

It's a world in which two races, the Pyross and the Hydross, confront each other.
For the Pyross, who worship the sun, water means only death and desolation. It erodes like acid. The rainy season also announces the awakening of dragons that pursue the Pyross deep into their troglodyte city, Orfalaise. Every day, the Pyross await signs announcing the return of the dry season. When the sun finally rises high above their heads, the Pyross set off on a crusade across deserts until they come to Amphibole, the city of the Hydross, the people that they hold responsible for their misfortune. The Hydross are the Rain Children. If they are destroyed, apparently a better world will arise, one without rain and free of dragons.
For the Hydross, the cycle is reversed: the sun’s fire transforms them into statues. Only rain can bring them back to life. Meanwhile, throughout the dry season, their bodies of stone are at the mercy of their enemies.
There’s no let up in the war between the Pyross and Hydross. Until the day that Skan, a young Pyross warrior, out on a crusade across the desert, sets eyes upon Kallisto…