This is whacky, crazy and couldn't possibly work idea. You have been warned.
How about a multi view point AP highlighting a war between Demons And Devils ending with confronting the manipulators behind them, all set in the obvious planes. Political intrigue, maneuvering and plots abound, some the players create, some they get mixed up in for good or ill.
First, What do I mean by multi view point AP
Well, it's an AP where you get to play the front half as Devils (or the Back half as Demon) meeting in the middle providing the opportunity for groups to meet up in games clubs and represent on the battlefields.
It could go something like this...
The players initially play their parents/creators as they are born to existence, giving a taste of powers they can aspire too. It reveals the early formative years of demons and devils, nurturing their animosity that feeds the on going war.
How bad do things go when you are a Devil with all the rampant drives of teen hood? What happens when the Demon discovers the pretty Devil out of his league and race?
Devils and demons getting summoned by different groups and sent on missions, many of which make them meet with differing mission agendas.
Now we start acquiring worshipers and truly come into our power. Boy, the prince of devils throne looks very comfortable, pity its occupied - for now... Well Demon Horde, are you going to let the devil grow so strong.
Mass skirmishes as you try to carve your land from fellow competing demons and devils. Then you become part of an unholy council... and move up the echelons of power through intrigue, manipulation and down right nastiness and murder.
So you plan and strategize, open the portal and march on the Paizo offices... Who is the biggest devil there and who the greatest demon? And can you wrest their position from them. Watch out for the insidious and evil ninja store care bears - they are the worst being both devil and demon combined.
Heh heh, how far did you get before you realized this was an in fun post ;)
I...don't think would work well. For one, AP's assume 0HD races. Secondly this seems like a hard campaign to run with a group of adventurers
Flavor wise, there is no blood war in Golarion, so the premise of demons and devils fighting each isn't going to work real well. I don't think demons and devils get along, but they wouldn't be focused on fighting each other, they would be focused on corrupting mortals. Which again might be hard to accomplish via an AP.
I quite agree, I even warned people in my first line of the post!
Especially that AP 6 part is too much - the CR of the creatures in that are just ungodly - even Mythic wouldn't help :P
Oh...hah...I didn't get through all the post before replying...whoops :)
I feel like I've witnessed something like this before... not that I'd PERSONALLY know... By the planes, no! Getting a blood war started in your cosmology is certainly no laughing matter, berk. Once it starts, it ain't ending any year soon. But, if you have a need to have those forces battle it out, I'm sure daemons can serve an important role... Not that I'd personally get involved, I have a business to attend to! Also, top tier mythic sounds like an option for going against the worst of the worst in AP 6. I dunno how it would play out, but color me intrigued...
Click the Spoiler on Final Engagement. Then you'll see.