So it's been stated and alluded to that a race of elves, or feylike peoples held dominion over the world at the center of the continent, where the Merinteri is now. These elves created many other races to serve them, being the progenitors of many peoples. 
I was thinking that these elves might worship Taranis to the extreme, going hand-in-hand with their despotic lordship over the slave races and the material world. 

The idea I had for my people, the calendians, is that they were offshoots of these elves that rebelled, with the help of Horomund, god of chaos. Their allegiance to chaos, and to Pathar and Sidhe, gradually led them down the path to their current debased, 'Chaotic Evil' state.