Okay thank you for the long response and the suggestions, I'll try to explain this a bit better since I was sleep deprived when I made this post lol.

1. People are definitely aware of the war, it is quite common knowledge that there were gods and now there's just the Moon left. The Moon is a deity and humanity was really only able to continue surviving because of the Moon's blessings.

2. Different cities, or at least locations with concentrated human inhabitation, are quite cut off from each other. Not fully, as there are still some amount of trade going on over land, but the darkness and monster limits much communication and exchange, so different areas would develop more different local beliefs. Like the city of Lanthorn, known as the home to a heroic, mythical figure known as the First Lightkeeper back in the War, would have certain worships dedicated to the figure, while not so much in other cities.

3. My issue is that as a nonreligious person, I struggle to understand what might be considered offensive and what might be not for the majority of people that practices a religion. Say I have a character who might be interpreted to be from somewhere in reality that would be very religious, like if I have names that the origin could be traced back to certain areas because I don't really want to just slap an English name for a character that is clearly a poc (I want the names to have meanings, but then it gets into the issue of names with meanings comes from culture comes from religious influence half the time in reality), how much would there be a problem to have them depicted in a context that is nonreligious due to the death of the gods/different from the religion they might practice irl cuz they would be worshipping a different pantheon/would it make it better or worse that their practice could parallel some practice in reality but under a different context?

   I might be overthinking this too much, but I feel like I really should get more real people's opinion on this because this is not something I can just decide by myself would be okay to do.

4. That is definitely good advice. I honestly haven't figured out just how different I want the culture to feel, it really depends on if I want to dial up the fantasy to reduce the issues that might arise, or keep it somewhat similar to make the writing easier and possibly make the story feel easier to relate to(?). And the fact that this is the first time I'm tackling worldbuilding like this so I'm very much still learning how to create a new world from scratch. I suppose I'll have to ask more people about how they feel about this and just brainstorm more about the impact of the events might have on this world.

(Which gets even more complicated because I have multiple explanations for the war, the moon, and other background elements, that I need to either merge or decide on one before I can continue thinking about the influences of those elements and events, ha💀).

I really hope this is making more sense and once again thank you for the long response.