The Factions

Marauders
Marauders are not an organized faction, but since they are mages I've included them here. Marauders are mages that have lost all sense of reality becoming insane (apparently, though they might just be unable to relate) in the process. They are effectively immune to paradox. Marauders are not suitable for PCs.

Nephandi
Nephandi are mages that have allied themselves with extra-dimensional beings of power. These beings (as a whole) seek to return to Earth and return it to the mythic age where demons, monsters, and mages were at the height of their powers.

The Nine Traditions
The Nine Traditions default protagonists for a MtA campaign, though the other factions are certainly possible. I'll cover these in more detail later.

Technocracy
The much maligned Technocracy has had a great influence making the world what it is today. Neither the Nephandi nor the Nine Traditions like the Technocracy because it has largely curtained their power. However, despite what the Traditions say, humanity is better off now than it was in the mythic age. The Technocracy steers humanity's progression and maintains the status quo.