(add this to the last big paragraph I sent)
Humanity is not the only species that thrives on the presence of the leylines. Fantastic creatures abound across Arcadia, strengthened by magic. The most terrible of these creatures, however, are the Skourge, nightmarish things that appeared at a relatively recent point in human history. Unlike most species, who form mutual relationship with the leylines, the Skourge seek only to consume. Areas with large numbers of Skourge cause the leylines to warp and the land to wither. Since their appearance, the Skourge have caused the near-extinction of many other plant and animal species.
Their presence has cause humanity to retreat and consolidate its presence to the Strongholds: massive, self-sufficient cities. Each city creates its own social and economic bubble behind its high walls. Cities compete with one another for mineral rights and strategic resources located in the wilds beyond their borders, where certain doom awaits the unprepared. To protect its citizens each city sponsors and supports the Arcadian Military Academies, schools where they train the next generations in the proper use of magic, science, and combat to ensure that humanity survives.
At the Academies, the students are drafted into platoons; each with their own name and number assigned to them. These platoons operate as a “family” of sorts. They train together, study together, and live together. In turn, they represent their city in competitions for resources, protect the city and its interests when called upon, and compete with one another for recognition and status.
You are a student at the Military Academy of Halcyon, recently drafted into the Thirteenth Platoon. The summer lull has ended, and training is about to begin again in earnest.