Creed of Ostreghast

It is said that during the unsealing of the upper and lower planes which eventually led to the War of Heavens, all four of the elemental planes experienced ruptures, dousing some of the mortal-kind with elemental powers, giving birth to the first of the Genasi.

These mortals who were both Material and Elemental were often abandoned as children, either by their parents or pressured by society to leave their home communities. Forced to walk Tal'Ria alone, and unable to reconcile their parents' identities with their own, the Genasi had no where to go and no mentor to show them their heritage or how to harness their powers.

It was the brass dragon, Derethig, who took in the fire Genasi Tychus Remble under his tutelage and protection, and later made it his quest to gather as many of the Genasi under his wing.

War of Heavens
During the War of Heavens, Derethig, Master Tactician was recruited by Jindryt, Lord of the Green to assist a group of mortals to help end the war. In the final battle at the Fields of Blood, the Dulgzeth-Jarm was quickly overwhelmed by the Lords of Hell and was unable to divert their attention away from the rest of the mortal troops led by the Seven Martyrs.

Derethig knew that the mortals would be routed if the Lords of Hell were not defeated, so with his small army of Genasi, Derethig called upon the elemental forces of the world to assist. It was here that the Ostreghast, a primal spirit made of all four elements, was brought to the mortal realm for the first, and only time.

Between the Dulgzeth-Jarm and the Ostreghast, the Lords of Hell were held in check against their forces, and the Seven Martyrs, with their mortal troops, pushed forward and were eventually able to force the devils back into the Nine Hells.

Aftermath
After the battle at the Fields of Blood, the Ostreghast dissolved into its constituent spirits and returned to its home planes. Derethig retired from military life and focused on training, raising, and recruiting the Genasi.

While the population of the Genasi have never reached the same number since the beginning of the War of Heavens, Genasi, genies, mephits, and monks wishing to preserve and study the elemental forces of Tal'Ria, took it upon themselves to establish temples and shrines devoted to the Ostreghast, and Derethig's teachings.