The Obscured World, a hidden veil imperceptible to non-magi, was created aeons ago to protect the lesser human race from the terrors that lurk beyond the fabric of the mortal world. It can best be described as a planet-wide barrier of perception which protects humanity from the fantastic and dangerous fauna that exist beyond their reality. Werewolves, vampires, dragons, sea serpents, and countless other magical creatures live and roam in the Obscured World. Most dangerous of all however, are the dark and terrifying demonic entities which, if allowed, can break through and cause irreparable ruin to the human race.
The magi, a race of humanoid magical beings, first existed as the guardians of this ethereal veil and their first duty was to safeguard the primitive human race from the terrors that lurk beyond their perception. However, the demons that exist within the Obscured World are as powerful and dangerous as the magi themselves, and the one thing that demons desire most is to break free of the veil.
For this reason, the magi and their demonic counterparts have never known peace. In the many magical academies throughout the world, students are taught to hate demons, and all are educated in the means to kill them.
As the ages passed and humanity grew in power and technology, the magi were forced to alter their purpose. Aside from protecting humanity from the monsters and demons that run rampant in the Obscured World, the magi now protect the Obscured World from humans themselves, who most fear will cause a great catastrophe should they become aware of what lies beyond the veil. To do this, many magi choose to live among humans in order to watch over them, and their exist countless magi communities hidden within human cities and towns.
For millennia, the Great Houses, the ancient bloodlines who rule over every facet of magi society, have enforced an unyielding decree which forbids any magus from revealing themselves or other magi to humanity. The First Oath, as it is known, is the most sacred of laws for the magi race, and breaking it comes with the most severe punishment imaginable-- the sealing of a magus' natural magic and the locking away of their own memories. Worst yet, those who break their First Oath are erased from the memories of every magi alive, and all traces of their existence are removed from the world.
A magi can still live among human beings, but they must keep their true nature hidden and must do everything in their power to keep it as such.
The ruling magisters of the Great Houses hold mastery over ancient and powerful magic and are hailed as the most sovereign of all magi. Due to this, the vast majority of magi live in both fear and awe of the magisters, and have lived under their rule for as long as anyone can remember.
In all the ages of the Obscured World, there has never been a revolt against the Great Houses.