Emma Frost was once a villain of the X-Men, being a member of the Hellfire Club. Now, she is reforming and joined the X-Men roster.
- Born to a wealthy Boston family which was basically like a reality show before reality shows were in vogue, with all the backbiting and absurdly negative/anti-social personalities.
- After about 20 years of going along with things, her cold and emotionally unavailable father offered her the opportunity to take the reins of the family fortune, which she promptly refused because she was tired of her father's mindgame-y crap, and also because she was a burgeoning telepath and could probably do better on her own.
- To that end, she went on to use some of her family's connections to get herself a job as a dancer with the Hellfire Club, because she wasn't above being a total hypocrite; she was a terrible dancer but since she was a telepath it didn't really matter.
- She made pretty good money as a dancer, which she parlayed into spending less time dancing and more time slipping in amongst the upper echelons of the Club; eventually, she managed to work her way into even its Inner Circle, becoming its White Queen. The costumes were basically the same as the ones she wore while dancing, for some reason.
- As the White Queen, she was primarily tasked with developing new mutant talent for eventual use by the Hellfire Club, and so she was given a school in Massachusetts to train these so-called 'Hellions'. In this role, she combatted the X-Men, the New Mutants, the Teen Titans, and so on.
- After a few years, things kind of went pear shaped thanks to a time-travelling psychopath named Trevor Fitzroy; as part of a 'game' between he and several other young, dangerous mutants, he tried to assassinate Emma and her students with a number of advanced anti-mutant robots from the future. Emma survived thanks to developing a new mutant power just in the nick of time, the other students were probably not so lucky, what with not spontaneously being made out of organic diamond.
- Although she survived, it took some time for her to recover, mostly because she was buried under rubble for a while and that meant detoxing from the myriad of controlled substances she'd been under the influence of during pretty much her entire tenure in the Hellfire Club.
- Once healthy again, she, rather than going back to the Club to make plans for revenge, wound up on the X-Men's doorstep, mostly out of guilt, but also because they are, presumably, actually concerned with mutant safety and rights, and the concept of mutant hunter-killer robots just appearing out of nowhere is pretty sufficient to make one care about such things.
Emma is pretty much a reforming supervillain, and while this clearly shows in her selfishness, her arrogance, her willingness to abuse her powers... she /also/ has a functioning system of morals that's mostly only developed and been nurtured relatively recently.
Having spent several years as a teacher of young mutants, she's developed a taste for the job and an affection for dealing with such personalities. She does not show it in the best ways - she is still sharp of tongue, haughty, and so on even when dealing with students - but there is an undercurrent of genuine concern beneath her nastiness. The loss of her Massachusetts school, of her 'Hellions' did quite a lot to foster her ability to think even vaguely of doing anything for anyone other than herself and maybe her students.
She is, then, a woman who's trying however vaguely to make up for years of being awful without /actually/ taking much responsibility for it; she will pretty much always blame substance abuse, her shoddy upbringing, the crowd she was with, and so on for her wrongs, regardless of how much merit those misdirections may actually have. In fact, even in reaching vaguely for absolution and reformation, Emma is /still/ a selfish and generally unpleasant person, but some of her negatives do wind up becoming positives when applied to playing a more heroic role.
Her aforementioned willingness to abuse her powers, for instance, comes with a thin enough understanding of the concepts of privacy and responsibility that she is unlikely to inflict brain damage willy nilly; what she /will/ do, however, is disable those who are in need of it without hesitation, wipe memories to protect herself and those around her without a care, and so on.
Far and away her best intentions revolve around mutant rights and safety, especially where adolescents are concerned. Her students were murdered by anti-mutant robots, after all, and while she's pretty well aware of who was /behind/ them... the fact remains that mutant-hunting and killing robots were still involved, which is problematic in its own way.
Emma is an Omega-level telepath, easily on the level of Charles Xavier, Psylocke, Martian Manhunter or Jean Grey. She's capable of broadcasting her thoughts over broad distances and to groups, of switching minds, mind control, creating illusions/altering perceptions, generating mental shields, inflicting actual physical pain via the stimulation of a body's nervous system, and more. She can also, of course, go for jaunts on the Astral Plane.
Somewhat recently, she's developed a 'secondary mutation', a diamond hard body with an 'adamintine luster' that simultaneously shuts her telepathic powers down and makes her nigh on immune to psychic assault. While in her diamond state, she becomes quite strong, able to support several tons on her own; she's also somewhat denser, and invulnerable enough to survive, say, an apocalypitc Sentinel attack unharmed. Her diamond form /does/ have a minute flaw that, when struck, will cause her to shatter.
Mostly Emma Frost's talents come from a mixture of having been really well educated and being an awful human being. She's learned multiple foreign languages(including French, Spanish, Latin, Japanese, Chinese), as well as a bit about art history, biology, history, all sorts of things from having been sent to the best private schools as a child and then, as an adult, taking advantage of her powers to learn things from any mind available.
She's also - perhaps surprisingly, for anyone who knows her but doesn't know her /well/ - is a pretty good hand with electronics; she doesn't approach, say, Tony Stark, but she's capable of producing devices to, for example, switch minds and mutant powers with other sentient beings or amplify mutant powers. She's also a fine business woman, stemming from her having run a fairly succcessful company of her own(as well as holding a degree in business administration, though how much time she spent in class to earn it is difficult to say).
Her time as a member of the Hellfire Club gave her all the introduction she needed to operating below the law, while pretty much her entire life has taught her how to bully or manipulate people into doing what she wants. She is also a pretty good teacher, between having a dubiously acquired degree and a fair amount of actual experience.
Also, because a ton of her time as the White Queen was probably spent under the influence of something and yet she still drove herself around without dying, she's pretty good at driving under duress too.
Emma is a fairly new recruit to the X-Men, but she's still a member in good standing. She's also absurdly rich from having been the CEO of a successful tech consulting firm, though it's taken kind of a bad turn what with her attempted murder kind of driving down people's confidence in the company; currently, what's left of it is being run by the board with occasional oversight from Emma.
She has contacts in the business, social, entertainment and criminal underworlds, thanks to her privileged upbringing and association with the Hellfire Club, and while she is no longer a member of the Club, she still has the occasional contact with its members and said contact usually doesn't quite turn to total antipathy. Also, she's spent probably about as much as several American families are likely to make in their entire lifetimes on cosmetic surgeries over the years to perfect her appearance, and has so far managed not to turn herself into the superhuman version of Heidi Montag.
Emma is almost absurdly self-centered, thanks to the combination of being rich, being pretty, and being really powerful. She believes in herself to the point where her confidence level could be dangerous, and conversely she tends not to hold much faith in /others/ without some reason to believe that they're worth it. She tends to come off as heartless, and that's just fine with her.
The biggest exception to this is her former students, the Hellions; she held them all in high regard when they were alive, and now they stand out pretty uniquely as a thing in which she feels as if she's utterly failed, and a thing which she's genuinely sad about--even if she isn't likely to display it easily.
Prior to when she joined the X-Men, Emma was the White Queen of the Hellfire Club, which put her in direct /opposition/ with not only the X-Men, but its students, the Teen Titans, and other heroes young and old; she's more or less a changed woman now, but it might not necessarily be easy for some people to just forget these things.
Finally, Emma had a nasty drug problem when she was a member of the Hellfire Club, but she's gotten better; now, she just has an incredible alcohol problem, but that's much more socially acceptable for a privileged woman.