Ok, so a few months ago I finished my campaign a long drawn out affair that brought the Party from level 1 all the way up to 19-20. Now they're all telling me that they'd like for me to step back into the DM chair when the current DM finishes his campaign up in a few months.

I've no problem with that. The only hitch is they all became attached to their characters and would like to continue with them. Problem is I've played Epic Level campaigns before, and I've grown to dislike them. So I've come upon this solution: A reverse leveling campaign.

It's something unique, whether it's a good idea remains to be seen, that none of them have ever encountered and it could likely add something to the game that's different from the usual quest-kill-loot-xp-level gain that they're all so used to.

And it could be done and tied into the campaign decently I think. During their adventures the PCs did manage to start a war between two major countries that could spill over into the rest of the campaign world. Near the end of the game they also attempted to stop a uberly evil Chaos God from being reborn and failed. I figure that all the carnage from the war and this new God could very tip the cosmic balance into the favour of chaos and evil.

Perhaps this new imbalance could bring things more into favour for the forces of evil. A divine curse could very easily come from from on High, cursing followers of the good Gods with a debilitating condition that slowly drains them of their abilities (i.e. levels) and perhaps their sanity as well, with the only cure being a quick conversion to the forces of evil.

Of course the PCs will oppose this, with their steadily weakening condition motivating them to try harder, while simultaneously removing the feeling of invincibility that high level characters so commonly have.

Now the only problem is how to work this out logistically in the game mechanics. I've never been as good with number crunching as I have with other things, so now I turn to the board for assistance. How would the rest of you do this?