I'd be interested in joining. Though I think that maybe you should change the Reaper a little bit; having it kill in a single day is kind of counter-productive if it's already extremely lethal. The longer someone's around, the more people they can spread it to. In my opinion, if the Reaper is the worst possible bioweapon I'd have it have a period between contraction and symptoms appearing where it's still possible for it to spread, and then once symptoms appear you die really quickly.

But I think I'll have a nation that worships some facet of the Old World in some way. Not sure if they'll just worship technology; I've been playing the After the End mod for CK II, so I'm tempted to have the stories of America's founding have been twisted to the point that my nation worships the Founding Father as deities, with former government buildings serving as their temples. But perhaps we should make the story take place a little bit longer than just 25 years after the end.