I'll be talking more about the ideas I have so far down below!
I'm pretty sure this has been done before, since this is a pretty basic (but still fun) AU idea. I just haven't really seen any fanwork from anyone about a Swap AU, so if someone has actually already done their own version of a Swap AU, then I would love to see it!
For now I'll just be sharing my own ideas:
As you can see, I definitely want to swap the Lamb and Narinder as characters! The Lamb now being The One Who Waits and Narinder being the last of his kind, meaning there is no more cars :( It also makes for another fun ship dynamic between them, with the Lamb being a callous yet playful silly God and Narinder being their calculated little Vessel, not admitting to his softer side when helping his Followers.
For the AU bishops, I thought it would be pretty cool if they are 4 of the slaughtered Lambs and I REALLY want to create some cool Bishop Lamb designs! But then I remembered, wouldn't that mean that the original bishops are the slaughtered ones then? But they're not cats like Narinder, so the original Bishops could just be something like regular followers, who eventually grow close to Narinder, becoming his found family. For the sake of having fun with this AU, I will make Bishop Lambs, unless I suddenly realize/someone points out that it really doesn't make any sense.
I don't have a lot more ideas yet, but I just thought about this idea on the spot: maybe the NPCs from the Map Areas could be swapped with each other. Like, swapping Plimbo with the Fisherman and Sozo with Midas, since Plimbo and the Fisherman should probably stay near water while Sozo and Midas really just a swap their obsessions.
Also no idea who the Mystic Seller should be swapped out with, maybe with their Disciples(?)
That concludes all my ideas so far! I'm open for any feedback or suggestions, thanks for reading!!!