Civilizations advance each at their own pace. The ones without rivals do not advance. They remain on tribal, primitive level, regardless of the passage of time. But when neighboring a powerful nation, there is rivalry that forces development. The weaker nation is easily conquered and turned into a colony for the stronger nation, the slaves gaining some resources and learning from the conqueror. As time passes, and nutrition and conditions in the colony improve from having a social order imposed by the conqueror, the subdued colony will eventually produce thinkers. It only takes a few exceptional minds, who will observe the stage of development their nation is at, who begin to question why they should be slaves. Such is the relationship between the desert and the mountain.
The mountain men have been slaves of one master and another master. Despite a capacity for the immense building of muscle, they never could contest their magic-wielding lords. And as these nations so tragically always find the means to cause their own self-destruction, the revisors have never enjoyed true freedom, always forced to switch masters as nations have perished.
Then everything changed. A man was born named Mondan. He led the revisors on a quest to freedom in the harsh wilderness, where no mage dared venture. The ferocious beasts of the forest were a better deterrent to pursuit than any wall or army. Against them, the supreme upper body strength of the slave laborers was optimal. And in the heart of the forest, they found the mountains.
The mountain city provides an endless supply of a mystical ore to the war-loving revisors. Possessing no ability or affinity to explore the language of creation, the empire stands on its own by employing armors and weaponry resistant to magic. The heaviness of these armors disables all other races from wielding them. The bone-crushing weight is counteracted with rigorous physical training. This requirement, to match up against expansionist rival nations asymmetrically, has led the mountain people to the formulation of a military culture obsessed with martial prowess.
Power over history is power over the future. The revisors have no respect for the past, as their history is so rife with humiliation and abuse. Their story, if not altered beyond recognition, could shed light to the events of the world.