Disclaimer: RWBY is owned by Rooster Teeth and Warner Media, I am affiliated with neither entity, this is a purely fan-made work.
Foreword-
Oh boy, where to start? This is my first fanfic, as well as my first real foray into creative writing. Like many fans of the series, I have been sorely disappointed at the dive in quality that it took after Monty passed. In this work, I aim to make some narrative decisions that are (in my opinion) more conducive to good storytelling than what we've gotten. Namely, characters aren't going to be mindless drones whose intellect and decision-making capacity are dependent on the needs of the script.
While the story is going to be told mostly through the perspective of a few OCs, the main characters we all know and love aren't going to be sidelined by any means. There will also be some changes made to what little established lore we've gotten. Realistically, the four kingdoms did not come together and sing kumbaya after an event referred to as "The Great War." If it was anything like ours (and in my canon, it WAS), then there would be serious geopolitical ramifications that would span generations. Dust is still a finite resource, and with hordes of soulless murder monsters prowling much of Remnant, there are only so many places you can harvest it. Border clashes and territorial disputes over mining rights only grow more frequent over time, with various private military corporations being retained by the four kingdoms in acts of "foreign internal defense." You can always publicly disavow mercenaries if things go belly-up.
I've also tried to apply some realism to the non state-affiliated actors as well. The White Fang, for instance, was already fairly similar to Sinn Féin and the IRA (the recognized political faction and the "disavowed' terrorist group). Here, the White Fang is a militant splinter group of the Faunus Democratic Party (FDP). In the vein of the Ulster Volunteer Force, we also have the human equivalent, the Sapiens Loyalist Force (SLF). With kingdoms and PMCs combatting and aiding both factions and their proxies, conditions are ripe for war.
Author's note: Yes, I do realize that I am applying "realism" to a fictional universe with magic, physics-defying magic dust, and force-fields generated by the human soul. If that term bothers you, then perhaps you could just call it "a consistent ruleset based on the way people and governments act in our world." But that's a bit of a mouthful.
