I like the general of a NPC anti everything faction, because I think this is actually a good oppotunity to get players to group up. To accomplish this, I would make them strong and expanding. First, - Their mission would be to wipe the continent town by town. - So in the beginning when they land somewhere by ship or aircraft, there is only a minimum threat. - Players might be fighting them for loot, but because they are only located in one region you could just avoid them. - Over time they send out troops to the other cities, which eventually kill the infected population and establish a base there. - If Players want to upkeep access to the cities, they need to team up and fight them of. - When the final camp has fallen, there will be ne reinforcement after some hours? day? somewhere else on the map. Second, - There might be nicer, maybe not repairable loot like tanks. - other stuff like some kind of "tracking devices" to gps-mark a vehicle to track it on the map. Maybe shootable over distance on that overflying helicopter? ;D
