Okay, here goes for Devil. (I'm not sure if this is overly dark or not, but I think she certainly fits her Arcana in both positive and negative senses.)
Also, if we're starting with the PCs learning to use their Personas, does that mean they don't need to have faced their personal Shadows (as in Persona 4)? I guess this sounds more P3-style, where some people just have the "potential."
Name: Amy Dorrance
Major: Business (MBA, former B.S. in Economics)
Personality: Amy is basically a hedonist. She's canny and does her best to keep pleasure from interfering with business, but given closed doors and half an excuse she's always eager to party -- in short, she's about as functional an addict as you'll ever meet. She's also remarkably nice about it; she has a keen eye for people who've been drinking too much or can't handle hard drugs or just aren't in the right headspace for sex, and tends to gently steer them away. She's likewise good at bringing people who can handle a good time out of their shells, although someone will inevitably say she's a bad influence. Amy's family suspects she's not ruthless enough for the business world -- at heart she really isn't, but she's disturbingly good at compartmentalizing her life, as always. Fighting Shadows will just be one more thing to juggle. Easy, right?
History: Amy comes from old money (by American standards, anyway). She's been in and out of trouble for most of her life, to the point where most people never realized she wasn't just coasting on daddy's wealth -- Amy would've made valedictorian in high school if she hadn't gotten suspended for a crucial week during senior year. As the best and brightest of her generation, she's being groomed to take over the family's wealth someday, and she's learned surprisingly well despite her fondness for intoxicants both legal and non-. She's always worked hard and played harder, and always somehow managed to keep her life balanced. Whatever her faults, she's well-read, brilliant at finance, trilingual, and can beat most people at darts while drunk and high.
Appearance: Amy is a slender Caucasian girl, slightly on the tall side, with nut-brown hair and bright green eyes. (She experiments with hairstyles every now and then, but long, loose, and wavy is her current favorite.) She's quite pretty, and tends to dress to flatter her figure, but even her "casual" clothes are pretty damned expensive by any normal standards.