I take the Hogfather approach: there is a finite amount of 'belief' in the universe... it separates the fallen angel from the rising ape, and when one thing is lost, belief fills the gap creating the supernatural, the superliminal, and the sublime.
If you haven't seen "The Hogfather", go and watch it. It's a bit long, it's very convoluted, it's British in humor... and it's 100% Terry Pratchett. Absolutely worth the time and a wonderful holiday tradition to watch.... also, pertinent to your question.

Voeskender was created by the deer worshipping... nature I believe. Which always struck me as slightly odd because to my recollection they always called nature "mother" and Voeskender was male.

It is worth wondering, did they actually create him or did they merely empower him and he always existed?
Did he start as a minor spirit of some kind and the deer worship made him a demigod? Was he a spirit from the same... realm as Odium and Charybdis? Or did he always exist like Gaia and just slipped under the radar?

I don't think anyone can answer that question for sure but Starscribe.