Spike’s role in this AU is as Twi’s adopted dragon son and personal assistant. Spikey Wikey’s a war child, or a child who’s like was directly affected by the war, and when he was found he was originally gonna be “put out of his misery” since his parents were found dead and there’s a prejudice against dragons in this AU. Instead, they end up throwing him in an orphanage, although death may have been a more merciful alternative at the time with the way the orphanage treated him and the other children
Twilight ran into him when doing a case investigating this orphanage; it turns out that this orphanage ran a child labor exploitation under the noses of the officials. Twi busts them, the owners are arrested and the children are either sent to better, more reputable orphanages or adopted. Spike, however, is rejected, and he ends up staying with Twilight as she tries to find a home for him. They fall into a routine that eventually convinces Twi that maybe he found a home in her, so when she asked if he would be okay with her adopting him, he didn’t think twice about accepting.
Now older, Spike is known around the firm as Twi’s personal little assistant. She doesn’t like leaving him home alone in Canterlot (she feels a little better about it if he’s in Ponyville) and while it’s against the rules, Twi disregards it and lets the young drake hang out in her office as she works. He finds her job absolutely fascinating and probably would like to be a cop one day given how much Twi’s impacted his life; in the meantime, he tries to help by bringing Twily coffee and bouncing ideas back to her when she’s brainstorming (he’s pretty resourceful and quick on the uptake for his age, and more help than a lot of Twi’s coworkers). Twilight had eventually begun teaching Spike how to handle a gun just in case something happens to her and he needs to defend himself without her, and that eventually shows to be a useful thing later.
Given how close he is to Twi, he’d be the first to know about Twi’s dealings with Rarity. Maybe he’s the one who convinces her to go through with it; they were down on leads and Rarity seemed eager to help, and what was the harm to at least hear her out in a public setting? They also knew Applejack; she wouldn’t set them up with the intent to harm them, connections to the crime world or no.
I’m sorry if a little of this got a bit jumbled; it’s pretty late here and I really should get to bed. But I hope that answered your question. :3
Does sunset shimmer have a role in this AU? Or perhaps have you already answered and I didn't see it
I did indeed already answer that but the answer was admittingly brief. So here’s an extended version:
Sunset Shimmer in this AU is a bit like Twi in that she’s one of the few cops that’s honestly working to try and keep the streets safer for the population. Unlike Twi, though, Sunset Shimmer first ran with a gang before ultimately leaving to become a cop. She wasn’t the leader of this gang or anything, but she’s experienced enough of the Underground to understand how the hierarchies work, who’s safer to interact with, who might hold the better information. Despite her leaving for the law her original gang probably don’t hold too much hard feelings toward her since she hasn’t arrested them, and now they act as inside contacts that eases some of her investigation. She does not work in the same office Twi does, but she’s worked with her and ran into her a few times before.
Is it strange that I sort of headcanon Twi as being male in this AU? I have no clear idea why, but reading over all of this I am finding myself doing so. Perhaps it's because this world is somewhat similar to the setting of the Wolfhound Empire series I'm currently reading, and Twi reminds me of the lead detective of the state in the book.
Not strange at all. To be honest, I’ve toyed with the idea that maybe Twilight is trans (MtF) in this AU. And in this time period, this might not be as widely accepted as it is in my regular headcanon, so no one outside her immediate family (aside from maybe Cadance) actually knows that she’s trans because: 1, it’s really none of anyone’s business unless she allows it to be, and 2, she doesn’t need, want, or deserve the hate she’d probably get if she’s ever outed to her current police firm. I’d assume Rarity would know because Pinkie hacked into her medical/birth records but she’s respectable about it, and she doesn’t dead name or bring it up unless Twi wants to talk to her about it. The perhaps she comes out to the rest of the Mane 6 after they’ve formed a strong friendship? I dunno (PS: If I get anything wrong about this please correct me on it). o3o
Have Twilight and Rarity ever had an argument over one of the latter's operations? Or perhaps over what Twilight thinks is one of Rarity's operations, but is actually a fame job by a rival gang (or maybe even the government) in an attempt to tank public opinion?
Probably moreso in the beginning of their relationship, when Twi, while knowing the police organization is corrupt, probably doesn’t see just how corrupt they are yet until Rarity opens her eyes to it. They could’ve argued about a case of Twi’s or maybe Rarity asking Twi to exploit a police officer, and at first she’s appalled by the idea because someone of the law is supposed to be there to protect. But while Rarity would know that’s just Twi trying so desperately to hang on to the idea that, maybe, just maybe, she isn’t a part of a really corrupted system and she can’t really do much to stop it if she follows the same system’s rules to a tee, it doesn’t make it any less frustrating. Still, Rarity knows Twi is no fool, so while she might not take the argument so hard other than some irritation after the fact, Twi might feel a bit guilty for her reaction, especially after the case reveals that, yes, the police officer Rarity pointed to was very problematic despite how they seemed at face-value, and that she was almost naive (or maybe desperate) enough to allow herself to believe that the police organization at this time isn’t a cesspool of corruption, brutality, and greed.
Does Twilight ever need to use Fluttershy's services? Needing to avoid tipping off her boss/coworkers she's working on something, or just trying to lay low for a bit, maybe?
In that little scenerio I wrote out about Twi facing off against hitman trying to invade her home is one of the instances. This one is more in the case of her attempting to lay low for a little while, so Rarity brings her to Fluttershy for treatment and it’s there she stays as she slowly recovers. She uses Shy’s services after that incident too, but she sometimes feels like she’s inconveniencing the young student. Fluttershy doesn’t mind her company at all.