So basically, I think everyone on the planet, with the exception of Geoff Johns, wants Cass back, if not as Batgirl, then as a 'Nightwinged' Batgirl. And aside from the small percentage of fans who hate Steph Brown for making not every panel about Tim Drake automatically about the epic love story of Tim and Kon, most people want a Steph and Cass team-up book. So, here's my pitch.
Tempest City, a sunny island resort/media mecca off the coast of Gotham. ("Gotham, Bludhaven, Tempest, who names these things?") It's basically L.A., but on an island. Still noir, but in more of a Veronica Mars/L.A. Confidential way than the Greg Rucka-y Gotham. But don't worry, when the sun sets, it's just as crime-ridden and sleazy as Gotham ever was. A la Miami, the city also has a sizable Cuban population, allowing for more stories.
For the record, Stephanie Brown, Cass Cain, and Charlie Gage-Radcliffe. Codenames: Spoiler, Black Bat, and Misfit. Basically, superheroes in training. Just because they're badasses, doesn't mean teenage girls should be going against the Joker. Same deal with Robin, only he has Batman watching his back. The Batgirls have each other. They all wear the same style of costume, your basic Babsgirl outfit, but they've all modified theirs. They're still recognizably the same clothes (like the X-Men movie costumes), but Steph has eggplant coloring, Cass has her ninja touches, and Charlie has a T-shirt and skirt on over her spandex.
Functionally, they're interns. They patrol Tempest, but they often go on "field trips" to Gotham or whatever exotic locale Barbara needs them in. CSI: Gotham. They go where Oracle can't, collect evidence, get witness statements (in disguise), and so on. At least, that's the plan. Things rarely go according to plan. Gotham's a big city, full of mob wars, supervillains, and occult ceremonies. Someone has to look out for the little guy, solve the small crimes before they pave the way for big crimes. That's the Batgirls' job.
By the way, the name? No one can agree on it. Steph calls them the Batgirl Mystery Team. Charlie calls them the Batgirls' Club (everyone else groans). Cass calls them the Birds of Prey.
Dramatically, they're family. Cass is the eldest sister, super-serious, dedicated entirely to the mission. Steph is the middle sister, able to run interference between the id and superego. And Charlie is the annoying little sister. Because for just about any trio, you need the Kirk, the Spock, and the McCoy. Leader, serious one, and silly one. So the Batgirls would be akin to Josie and the Pussycats, Charlie's Angels, or Glee's Unholy Trinity. If it works, don't knock it.
Business-wise, they all bring something different to the table. Cass can kick the ass of pretty much anyone, but she's not yet much for detective work. Steph can hold her own in a fight and figure out the plot to any given episode of Law & Order: SVU. And Charlie is comedically useless when it comes to fisticuffs, but she's actually something of a genius ditz when it comes to mysteries.
Oracle – Our girls' mysterious mentor. The Charlie to their Angels, Barbara isn't yet ready to trust them with a face-to-face meeting, so she's set the girls up in a swank beachfront property in Tempest, where they're literally at arm's distance. So, you know, they'll work on that. She's the team's dad, balanced out by…
Black Canary – Field leader, the Cyclops to Oracle's Professor X. Only sleeping together, which, let's face it, no one wants to see Cyclops and Xavier do (he'd be cheating on Magneto!). She's the team mom, meeting them face to face, backing them up, and dispensing emotional wisdom.
Zinda – Pilot and the official Batgirl Mystery Team cool aunt. Unlike the Birds of Prey, she'd pretty much stay in the plane reading trashy paperbacks. This is the Batgirls' show, after all.
Flamebird – Bette Kane, superhero socialite. Megan Fox in a cape. She used to be a vigilante—maybe—but she used her splashy entrance to break into Tempest City show business (it's the Vancouver of the DC universe) and now stars in her own series on the CW. She still considers herself a superhero, and her publicity means that a lot of useful information finds its way to her, so she acts as "Huggy Bear" for the Batgirls. Cass and Steph greet her with derision. Charlie is her biggest fan.
Ted Kord – I always liked the idea of Barda on the BOP with Scott as the Q to her very loud James Bond, but since that won't work in this setting, Ted Kord! He's the hardware to Oracle's software, able to fix up Zinda's aircraft and the Batgirls' gadgets, as well as give them whatever sleuthing tools they need. The team's big brother. He watches out for them, even if they don't like the idea. Most likely to criticize what Charlie's wearing. ("You don't see Supergirl dressing like that!" "Supergirl wears a belly shirt and a miniskirt!" "Not in this continuity!")
I'll pause here to digress: In fanfic, slash is all well and good, but for actual ends-up-in-someone's-hands writing, you don't want everyone to be a lesbian. It gets a bit self-indulgent, plus people would wonder where all the gay men are, and "I don't want to write about Superman and Batman canoodling" won't cut it if Supergirl and Batgirl are flirting up a storm (even though they hardly know each other… seriously, do people really ship that?). So the aim here, personally at least, would be for at least ten percent of superheroes, men and women, to be queer. So while Babs and Dinah are totally married, Cass and Steph are just good friends. That just makes sense dramatically speaking—if Cass and Steph got together, they'd be the perfect couple, but if Steph's in love with Tim, you get the drama of a romance between an ovary-possessing teen girl and a borderline asexual dude. And while Steph would be understanding and reassuring entering into a relationship with Cass, Cass doesn't have the same guarantee with literally anyone else. So you pair her up with, say, Jaime Reyes, there's automatic conflict and tension.
And yeah, I do have a few thoughts on male heroes who would work as gay or bisexual, but this post is running long as is.
Basically, a lighter, fluffier Batman comic. It's still Gotham, but things don't tend to end with orphans getting their throats slit, so much as parties! On the beach! In becoming, yet reasonable, swimsuits! (Why would you buy a transparent bikini, Kory, what's the damn point?
) Think Nancy Drew Goes To Gotham City. In fact, if I had my druthers, the comics would be mocked up to resemble those classic old Nancy Drew covers, at least once.Just throw Mr. Miracle in there somewhere.
Okay, Fourth World: The idea is that Scott basically stumbles into a young adult series for girls, getting the rare chance to play straight man. He's completely baffled by two sorority girls and one kinda creepy ninja running around making references to "The Case of the Missing Candle!" And since the Batgirls are a globe-trotting adventure team, he could cross paths with them as the plot demands, always taken aback by the new progress in the teenage girl soap opera. ("Wait, I thought you and Tim were together?" "No! I hate him!")
Then the "Batgirl Mystery Team" issues sell so well that even DC Comics sits up and takes notice, and Gail Simone is put in charge of a spin-off aimed at teenage girls. The winner? Everyone.