Firefly is an orphan. Born to parents who were two of the most skilled Storm Pegasi of their generation, their teamwork had gained them praise and admiration across the spectrum from their peers both Storm and Weather pony alike. When they had their child and felt it was time to teach her the family trade they took her far out from civilization to learn. There in the ocean skies they showed her how to make storms, how to herd clouds, how to tame those that rage and thunder and how to own the sky.
Unfortunately, weather becomes unpredictable, as any weather pony should know. Storms have a way of taking their own path, and the one in which they trained became an embodiment of natural fury. The family was battered and forced to take refuge on a spot of land that could barely be considered an island. It raged for hours and when Firefly woke, she found her parents did not wake with her. They had been beaten by the storm protecting her from its winds and debris, injured already in the gale winds and hurricane twisters. They did not survive the night, though they gave their lives so she could keep hers.
Firefly spent a few days alone on this island, unsure what to do with her parents save to hope they would rejoin her. Eventually she was found by rescue teams knowing the family was out in that storm. With her parents gone and pity taken upon her she was placed in a good home, but she could not stand it, still wanting to be with her parents and growing up without them, she rebelled over and over even at an age barely out of her foal years. Anger in her heart, she became a bully and picked fights with other pegasi often, especially should the topic of her parents be broached. More than one wing was broken or leg bruised by her as she defined her personal space by the reach of her hooves.
Finally she ran away, taking her meager possessions with her, and she disappeared beyond Cloudsdale. Living alone as a filly she continued the skills she learned from her parents, training herself alone in dark forests to control the weather, to master it, so she could bend it and keep it from taking another family away as she lost hers. In reflection she oft felt this cliched but sadly quite true and a needed thing. She got good at it in fact, so she was often referred to as an example by storm pony elders teaching the younger generations. She never remained in one place however, travelling from city to city, town to town, until she came to Ponyville.
In Ponyville she's started to open herself up slowly through the help and efforts of one particular pony who shall be mentioned a little later..
Firefly is collected and forcefully paces herself through things now. In her younger years she allowed her temper to control her, frequently getting into fights and brawling with other foals, typically colts but not discriminating by gender and fine with hitting a filly if she had it coming. Jabs at her parents were the fastest way to gain her ire and kids will be kids. Since growing up and doing weather work she's learned to keep her cool and think about things at least a little bit before going forward. Further since elder Storm Pegasus outnumber the young she has been drowned in sayings and tradition for many years now, the wisdom of the ancients shared over a strong cider after calming down a rampant tornado.
She is a little shy to new ponies at first, and listens a lot rather than speaking. Once engaged however she opens up quickly and will talk to new acquaitences like best friends though this doesn't really mean she's letting her guard down, just conversational.
Her primary traits lie in her loyalty to those few she holds dear and her mindset of a guardian or protector. One of her vows on taking her parents work was to never let a pony suffer loss as she did, so where she feels she can be a shield or a rampart she will leap to the aid of those she sees in need.
Firefly is a pegasus, of course, but not just a pegasus. She's of a breed known as Storm Pegasi. These are a little bigger than the average pegasus, a little heavier, and denser on the inside. They're built for dangerous weather and back in the day were always seen on the front lines of pegasus armies. This storm pegasus, is hot pink, which might take away from the intimidation factor. She's not a tank or anything, she only carries maybe an extra inch or so if that over the average pegasus, but it can be noticed. It's all in the bones. If you were to just pass your eyes over her it would almost look like a certain other pegasus who maybe fell victim to a paint trap, but no, it's not.
First off her cutie mark is entirely different, a flank adorned by two parallel lightning bolts that sparkle against her in blue like the ocean waters. This is a shade shared by her mane and tail, her mane in particular something of a mess but she takes efforts to straighten it from time to time. Her eyes are violet, and sparkle with alertness and intelligence though they also seem distant a little, lost in something internal. She's not generally boisterous but if you get her going, yes, she will brag your head off. Talking about rainbows ironically might also be dangerous, as these are her favorite of things.
Firefly doesn't know too many ponies but has met several. Some stand out in her mind. Some might need to shake her a bit to remind her about it. (That means if you want to be on here, shake her and remind her about it.)
<unnamed> - Firefly is in love. This pony is unnamed for their own privacy right now, but she loves this particular pony with everything that she is. Her entire life has been spent boxed in and doing her work but only really living for herself and never really creating bonds. This pony was, different. Different enough to stay in Ponyville and talk to, different enough to get her to slowly relax. Different enough to melt her soul and now she lives not just for herself but to make this pony smile, to make them as happy as she possibly can and lift their burdens from them. She has vowed to protect them, keep them safe, and be a companion that they can rely on no matter what hardships they endure.
She loves this pony utterly and completely, through good and bad. Even if they fall she will be there to help them up and be their support. Her heart is loyal to this pony and frankly... she's happy that way, and would follow them to the ends of the world.
Fluttershy - A pony she met who when she speaks her mind she can do it with razor sharpness. She's also an incredible sweetheart who seems to have... dyed her hair rainbow? Does she have a crush on somepony similar?
Gilda - She came over one time to a place drunk and mistook her for Rainbow Dash. Firefly's half flattered and half insulted but completely amused. Teasing her about Dash seems to work great.
Princess Celestia - She's actually spoken to the Princess once to ask her a small favor. She seems strangely nice, considering she's a Princess.