In Ultimate Marvel vs Capcom 3 Heroes vs Heralds mode, are the cards I can obtain determined by the mission zone? Or is there a possibility for me to obtain any card in any zone? If it is determined by the zone, where can I find a list of what cards come from which zones?
Check out this blog here. It has a grid with a list of all the cards and in what location they can be obtained. Obviously I haven't check every single location, so your mileage may vary, but it's certainly a good place to start.