Overview
One thousand years prior, this world was ravaged by a war so horrific that it even gave the three goddesses at war with one another pause. Seeing that there was no hope for any one of them to emerge victorious without destroying everything, they agreed to seal away their powers and exile the magical esper race from the world at large forever.
Of course, not all knowledge of magic or espers was lost to time. Eventually, through a combination of human curiosity and the espers' own restlessness in confinement, the secret was compromised. First, by an unlucky intruder that stumbled wounded upon the esper realm and was nursed back to health. Then just a couple short years later, the esper realm was once more intruded upon. This time by armed men who captured many espers and made off with a unique half breed who served as a template for the creation of the first new magic users in a thousand years.
Fast forward several years and the newly minted Gestahlian Empire, riding the wave of their peerless magitech, has begun a campaign of tyranny that threatens the peace of the World of Balance once again.
The ambitions of the Empire certainly won't be stopped by mere borders or even by the limits of their world and due in part to the resurgence of magic, ancient scars left over from thousand year old battles have begun to show promise as potential gateways to other worlds ripe for exploration and exploitation.
Of course, the Empire isn't the only faction at work in the world, though it's certainly the most dominant. The kingdoms of Figaro and Doma as well as many independent towns are at least at odds with or openly at war against the Empire, with a group of rebels calling themselves the Returners doing what they can to slow the advance of the Empire's so-called progress. Each in their own way is likely to reach out into the wider realm as they're able, seeking aid against an overwhelming foe or probing and assessing a potential new front of an already monumental war, likewise seeking allies or perhaps an easy conquest in the name of the Emperor.
Espers
Espers are a race of magical beings that were created specifically for combat during the War of the Magi. Coming in all shapes and sizes; some bestial, some more humanoid and others quite unusual. Likely because they're believed to be extinct, their crystalline remains command a high price and are highly sought after by the Empire.
Magitek
The Empire's edge in it's apparent campaign of world conquest, Magitek is derived from everything that could be learned from what was left of civilization after the War of the Magi. By using this knowledge in combination with espers as near limitless fonts of magical power, the Empire has secured a means to power their tremendous industry and manufacture weapons of war that haven't been seen for a thousand years. Powered aircraft, walking tanks and even magically augmented soldiers.