I've yet to witness armageddon, I only played normal games (without the option that doubles AC effects) and while I've seen Infernals and Mercurians, neither side left much of a lasting impact on the world in any game.
I hope there's going to be a scenario which is almost like an open game, but a modified armageddon is bound to happen at turn 400 or something.
Since it's a scenario, it'd be even cooler if there'd be a hundred turns or something worth of "influencing" from both sides, kinda like in Babylon 5 (the Vorlons vs. the Shadows).
Civs would need to align with either the Mercurians or the Infernals, which in either case would mean signing pacts to cease cities, population etc. in excange for protection/cooperation.
(i.e. once both sides actually manifest, they'll get a number of cities instead of one, plus military units etc.)
The alternative would be chosing neither side but staying neutral, but this would mean having to fight both sides plus all their lackeys, eventually.
Both coalitions should get no hell terrain, but the neutrals would.
Good and Evil camps would instead be plagued with spawn-sites of the opposing camps and inevitably war with everyone on the other side.
And both sides should have to hurry to resolve the conflict, because the Infernals would lose patience and temper as time went on and demanded more and more "volunteers" for their war effort and sacrifices to appease their demons. The Mercurians, on the other hand, would get more and more zealous, declare ordinary folk sinners and demand them executed. (Both resulting in the loss of population and eventually entire cities).
Neutrals would be the only camp with time on their sie, as more and more refugees from both camps would bolster their numbers - and they should eventually get some tech to enable them to drive back the hell terrain which would initially hit them very hard. As the conflict dragged on, units of Good and Bad camps would get increasing chance to switch allegiance to a neutral player.
In rare cases even members of either camp could see the error in their ways and switch to the neutrals instead...
I'm not sure if such a scenario is feasible, as I don't know jack about the lore, but I think it'd be damn cool to play.
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rezaf