Demons are always NPCs, except in a few very unusual circumstances (like a 'naive passer', which is a demon that thinks it's human...)
And for your entertainment, here's the very first setting post I used in that other attempt. Our PC was a somewhat scatter-brained Poet motivated by his romantic attachment for his muse, a beautiful woman who was (alas) also utterly mad...and thus unto the Dreaming in search of her...
"It is every city and none, vaguely Victorian and possibly Edwardian, too vague and fogbound to be clearly labeled by even the most precise of chroniclers. Here there are fairy-tale castles built by the eccentric and mighty, palaces to their own egos and lust for distraction from the cold and growing anger of the underclass bent to labor in the dark and forbidding mills just across the river. Here, also, there are mazes of alleyways surrounded by grim and joyless tenements. Here a park, open and green; there a cobbled street where a thousand souls pass by every hour, shoulder to shoulder, and above it all a castle on a high hilltop that oversees all as if brooding over the press of humanity along the banks of the icy river far below.
The city is many things to all hearts--the jewel of the realm, a wretched heap of misery and despair, a vast market of possibility, a vague and dreamlike place where a soul can lose the past and be remade whole to order, a shoal that breaks all vessels that come too near.
This is the city of winter."