Imagine a world tree formed of the innumerable planes orbiting innumerable stars. A living, breathing, connection between planets amidst the abyss of space. It is here that the Earth you and I know, is but an offshoot. A stray 'seed' of the greater plane of Eden.
Long ago the angels of the boughs, the demons of the roots, and the dragons of the trunk all fought across the many planes. It was through this conflict humanity, monsters, and the Earth itself, was created.
The year is 20xx, Earth is much the same but with many magical creatures hidden in the shadows of power and alleyways. Humanity's civilization has marched forward with werewolf packs, vampire conclaves, and witch covens following suit, discreetly guiding life as we know it.
A grand stage for but a humble group of mercenaries, misfits, and trouble-makers to put on a play. Of adventures, covert dealings, magic, and money. All in the name of making a life for themselves on a rock in the abyss, a branch of the world tree.