The Dictionary of Mu describes the world of Marr'd, a broken, bloody desert that will not support its occupants/parasites much longer. Most Marr'dian cultures (though not all) are hell-bent on getting off of this red rock and into the heavens, whether by magicks, wing, or lost science. Marr'd and its inhabitants are detailed within the Dictionary -- an incomplete collation of the dying world and its nations (Atlantis, Arcadia, Hy-Brasil, Lemuria, and Olymon, and most likely more).
Sorcerers are the greatest hope and the greatest damnation of Marr'd. On the sweat and blood of the sorcerers this ball of red dust will either rise above its history or be damned and barren. Yes, Marr'd is a brutal place, but you need not wallow in that. There is the potential for sorcerers who have summoned and bound demons in hopes of making something better for this world... but that's up to you.
Demons are the spirits of the dead, be they ideas, people, cities, or empires -- one cannot throw a stone without hitting such a spirit -- slumbering, waiting for a summoner to bind them into the cruel world that broke, forgot, or destroyed them. A demon can simply be the spirit of a dead entity -- a ghost, an idea that has faded from the consciousness of Marr'd (like the Written Word), and entire eradicated people or warrior caste or even a form of entertainment long since banned. It can also be an entity that is dying, like Marr'd itself -- still alive, but with enough of it dead to warrant a spirit, growing in power.
On Marr'd, Humanity is the character's hope for the future.
New Dictionary Entries (from play, please)