I wrote a bit of a pantheon for worldbuilding Your Fate Like Clockwork, but only ended up referencing the deities significant to the story.
The Church of the Night Mother: Not to be confused with the heretical practice of worshipping the Night and its many monsters, practitioners under the Night Mother pray for deliverance from Hell’s rising horrors. Most people pray to this deity to some degree, but monster hunters especially rely on the Night Mother’s compassion more than any other figure, as their work calls them to hunt humanity’s own predators.
Within the Church exists a faction deemed the Cleanse. Hoisting the banner of a dismembered raven in defiance of ill omens, hunters of the Cleanse engage in indiscriminate slaughter of entire populations at the first signs of evil taking root. They face little criticism for this due in part to their efficacy, but mostly for a fear of their unopposed absolutism (a point the protagonist takes issue with as the Cleanse’s judgment of what constitutes evil often includes technological and medical advancements).
The Serpent Cult: within the valley the story takes place in is a lake whose waters reflect no light. Beneath the lake, it’s believed, lives some kind of snake, constantly on the verge of starvation after a maiden of light reached down its throat to pull the moon’s reflection out from its stomach. Fearing what could befall their fertile valley if the Serpent should decide to eat itself in its hunger, folk from the nearby town have paid monthly tributes of flesh to the lake for generations, some of the elderly missing entire limbs by the time they die.
The Idolatry of Wolframme: within this same town is a secondary practice, more reverence than worship, but considered equally heretical to those outside the valley aware of it. Throughout the valley are signs of an old war hero who left enough of a mark that artists, sculptors and writers still venerate deeds done (though so much of the town’s history has been lost at this point they no longer have records of anything more than a name to honour, and there seems to be disagreement between Church and State over what gender their idol even was).
Other than maybe a reference to a figure known as “The Almighty”, the rest of the pantheon went unused. Given I may want to write a sequel someday, I’m not gonna say anything solid about the rest, in case I wanna make changes.