I mean, we've seen Ruby snap in the show after the whole Pyrrha ordeal, so I thought "Okay, but what if she didn't go deus ex machina, but rather just... "insane". What if she's so detached from reality because of the things happening around her that she acts on impulse?" (Plus, Remnant is the perfect universe for a Medieval setting)

Yang's storyline basically revolves around finding their father/parents to kick Ruby off her temporary throne; also her main focus is to help Ruby get a grip on reality again.

Weiss's storyline revolves around the consequences of Ruby's actions in a grander scheme, as well as show things from an outsider's perspective.

Blake's storyline connects all four storylines since she understands the threat that is Ruby and sees it as perfect opportunity to get rid of Monarchy alltogether, and is thus able to team up with the other characters. (Also she doesn't lead a pro-Faunus organisation, but rather an "Anti Monarchy" organisation. Humans can join it too.)

Think of it as the AchievmentHunter Minecraft Kings AU, but with RWBY characters. Ruby = Ryan "The Mad king" Haywood; Yang = Michael "Mogar" Jones; Blake = Jack (Kinda, since she's rather passive), and Weiss = Geoff (kinda, since they both have the role of a Knight in most AUs)"