My friends and I run evil player based campaigns exclusively and always love to find wicked twists to put on great adventure paths. I think I figured out a great one: Run Savage Tide with the PC's as chief agents of the forces of law and evil. (The group seems especially interested in the Whore Queens)
First I think I'll leave a few of the old 3.5 demon princes in it, possibly getting rid of them in the climax as a tie in to the backstory of the demonic hierarchy in the pathfinder setting. I always felt like Malcanthet was destroyed and replaced by Socothbenoth as Queen of the Succubi, and Grazzt somehow dethroned and replaced by Noticula. And Demogorgon was destroyed in the savage tide finale.
I imagine it starting out with a direct incentive to find out what Demogorgon's cults are up to on the material place, as opposed getting caught up in it randomly.
So I'm asking everyone what points you see changing or what some good elements may be to also throw in or take out. We love the lower planes so I thought brainstorming this concept could be a fun topic and helpful for my campaign.
The only big changed seem like they might come later. Could the PC's disguise their ultimate allegiance from the demon lords they seek aid from? Would that many of them care? I remember anyone who replaces Demogorgon becomes chaotic evil, but is that true if they are a lawful evil outsider? Could the hells try to bring some of the abyss under the forces of order?
Aside form all this I'd like to find some interesting twists to bring in earlier on in the campaign.