You may have answered this before, but how are you handling characters that don't believe in starclan, like mothwing and cloudtail? Personally I thought it was interesting when reading the books, considering cloudtail, but only to a point because it's very hard to write atheist characters in a setting where there's undeniable proof of the gods/spirits/etc. Like, how did they explain the literal forces of heaven and hell battling on earth??
As An Atheist Myself ™ I have a lot of feelings about the two of them. I think the short answer is just that in a setting where gods are literally undeniable facts of life, "Atheism" looks more like Dystheism, the belief that they exist, but are not worthy of worship.
That seemed to be the conclusion at the end of Mothwing's... i forgor the name of her novella 💀Mothflight's Blaspheme Boogie. It's actually why it's one of my favorite novellas, I really like the way it closes out with Mudfur trying to sales pitch StarClan's goodness to her, she doesn't buy a fucking penny of it, and ultimately concludes that the comfort it provides to her Clanmates is valuable to them but doesn't have to be for her.
So that's how I want to handle them. They have an outsider perspective to the fact that this is a theocracy, based on gods that can be vindictive and vengeful. Scourge/Iceheart is also joining these two, he actually is going to have a minor but important role in Squirrelflight's Horror as a ghost basically giving insight to what happens when you don't worship StarClan when you die.
With him and Mothwing I really know what I'm doing. Mothwing is insight to Leafpool, especially in TNP where she is now a POV, and observing how the though of StarClan influences the behavior of the cats around her. Scourge is killed in the Great Battle and serves as a ghost to witness their trial. Cloudtail...
Cloud's still evolving. He's going to be a supporting character with Ferncloud in her SE and exploring the feelings he has towards Ashfur, now his apprentice, becoming a villain. How he did his job perfectly, raised him with a deep respect towards the warrior code, and that lead to the person he is today. How he couldn't have done things "better" because this DID raise him the way his society expected him to.
But his dystheism is kind of secondary to that. I think the story I've got for him is fine so far, but it needs more of an 'ending' that I can't decide on until they finally kill him in the main books.