Re: Interest check: M&M/WoD modern era demonic apocalypse
Anyway, more on the setting. There's three main kind of settings for this kind of game.
The demon-controlled lands, most of Central Europe, are a wasteland where demons roam free, killing everything that moves. Unfortunately, they're also a valuable source of knowledge on demons themselves, so humans have to stage expeditions there from time to time. A game set there would be basically a survival horror.
Then, there's the rest of the world which is, thankfully, still under human control. This doesn't mean that demons don't try infiltrating these places too: careless humans often get tricked into summoning a demon they can't bargain with, and they usually end up in thrall of the creature who then is free to go on a murderous spree or, even worse, to go into hiding and start influencing mortals. Specially trained police forces are constantly on the watch for this kind of threat, and a game set in "civilized" lands is likely to be based on investigation.
Finally, there's the frontlines. There, WWII never truly ended. Fresh troops are constantly sent to the front to counter the demons' advance, but the huge cost in human lives is barely enough to stall them. A game set there would be war-themed.
In more civilized lands, people are tested at a young age for magical potential. Those that test positive are drafted in the military as summoners in training, and are taught how to best bargain with a demon in preparation for their binding ritual.
On that night, the would-be summoners undergo a ritual in which they summon a demon using their blood. In most cases, something answer the calling and shows up for bargaining.
Most of those that summon something manage to bind it, one way or another, although less bright recruits might bargain poorly. A few botch the ritual; the demon gets free and kills them before being put down by the instructors. And some more don't manage to attract anything. These "orphaned" summoners end up on the frontline as foot soldiers, equipped with a magical blade. Ranged weapons can't be enchanted because the required symbols need to be etched on the ammunition, and they deform when fired, so these guys are sent to fight demons in melee. As you can guess, their life expectancy is minimal.