I'm just at the stage of basic mechanics: everybody's got Attack, Defense, Aura, and HP stats.
Damage taken = your attack - their defense. HP is very small compared to Aura, which gets depleted before HP; in the somewhat unlikely event that anybody winds up losing all Aura but still at full HP, they can still talk but they can't lynch.
Any missing HP, no voice or vote; effectively dead. Overkilled hard enough to deplete all HP or more: actually dead, and extra Grimm spawn next Twilight phase.
Grimm will take the place of an Independent faction, and (individually) attack randomly after Night phase is over but before Day phase begins - in a dedicated "Dusk" phase, so you can choose to attack Grimm instead of players during Night phase, and thereby decrease the chance of getting damaged by them that Night.
Additionally, everybody (with one exception) gets a Semblance, a role ability which costs a varying amount of Aura to use.
It may seem sorta convoluted right now, but it should all make pretty perfect sense once it's all laid out and you get that role PM.
But as for how far along I am with ensuring that, the bulk of the number-crunching and balancing work has yet to be done, and there's gonna be a lot of it required to make this a fair, fun, and reasonably intuitive kind of game. Additionally, I've gotta put real hard thought into whether I'll be able to avoid major spoilers while I do all this, or whether to just drop that pretense and operate under the assumption that anybody who cares to watch the show would have just done so already. (Anybody has any input re: personal preference, for this, please feel free to chip in here so I have a better idea of what to work towards.)
And I'll also want to come up with a better solution for making sure show-watchers don't have any extra advantage over non-viewers - something I think I did pretty well for One Punch Mafia, but can't necessarily replicate here, - besides just giving all the role info away from the get-go.
Long story short: There's a lot of work to be done on my end, and my ridiculous work schedule hardly even allows for that kind of effort until my contract is over in a couple of weeks. So yes, right now is definitely a good time to run another game instead, especially if it's something simple and classic like some good ol' vanilla.
Edit: Also, high probability of future "PWPY Mafia" would probably make it worth running the RWBY game on its own, let alone how fun I think the actual game itself could be.