This just jumped into my head, so I’m frantically writing it down in gaps between feeding twins. Excuse unseemly brevity and enthusiasm.
A setting where the PCs are the Icons. Each PC is the ruler/champion/symbol/figurehead/chosen one of a particular race/culture/faction. Instead of Icons, you take TWO qualities of your faction that might or might not show up in a given session. So, if you’re the Werewolf Prince, you might take Savage Nature (positive) and the Moon (conflicted). Each game session, you roll for Icon benefits as normal; on a 5, you OR your faction can do something awesome with that “quality”, but at a cost. 6 means it comes without strings.
The twist – you then take a third quality from one of the other players, but you have to have a different relationship with it (or stay conflicted). So, if you’re the Shepherd of Worlds, you might take my Savage Nature quality as a negative – you want to tame nature, I want it to remain red in tooth and claw. (Maybe each player should only define one icon, and take two more from other players, to bind everything together.)
This concept would probably work best starting at 5th level, where the PCs have some real power under their belts, and I’m not quite sure what sort of adventures the PCs actually go on. Presumably, battling against shared external threats to their cultures would be a big part of it.
Now that I write it down, I realise that I’m channelling bits of the primordial setup of D&D (back when it was closer to Fantasy Diplomacy in Blackmoor) and Callisto. Good antecedents to have.