Against which factions is it easier for demons to fight, and against which is it more difficult?

This makes playing against them even more interesting. Most people prefer to play as factions that are easiest to control, but I think there are also quite a few fans of complex factions (although fewer) – they are few, but they are true masters because you can only learn something by playing against a more challenging opponent (in this case, by playing as a faction that is more difficult to control).