Thundergod versus Dragon
A number of ancient cultures have an epic battle pitting a hero god (often a storm god) versus a great dragon - Thor versus Jormungandr, Marduk versus Tiamat, Baal versus Lotan, and many others with variations. To echo this, the creation story of Galhadria has a similar conflict.
In this creation, the Great Old Ones (yes, those Great Old Ones) existed before the creation of the universe; they were driven back by the primordial dragon Tiamat who killed, scattered, or otherwise knocked out these ancient cosmic horrors. Then she ignited the sun with her breath and brought her own brand of order to the chaos. Soon enough she was opposed by Gromm, the father of giants, who naturally hurls lightning around. Into this ancient rivaly the Galhadrian mythos adds Shalokar, a great fey lord and trickster, who plays these two off against one another.
These three created most of the mortal peoples of the worlds, and fought over all creation until the coming of the younger Powers, which will be covered at another time.
These three archtypes - the storm lord, the devourer, and the trickster - are archetypes which have parallels in most existing cultures. If they seem somewhat familiar, though should - the structure of Galhadria in all things should seem familiar yet different at the same time.