It is not meant to be assumed that these iconic characters have a coherent history together. They could show up in groups, with each other, alone, working against each other, etc. They could die repeatedly. They'll still show up. They're icons, not actual PCs.
Anyway, here's the first of the iconics, including some quick and dirty visual representations I was able to snag off the internet. In the ideal world, I'd be a great artist myself (instead of a mediocre one), or I'd be able to commission art from a great artist to represent these guys. But, this is the real world, not the ideal one, so I've had to take whatever images a google image search could give me, crop them, maybe manipulate the color a little bit, and that's about it.
Biella comes from the Marçalez family, a minor noble family from Sènt-Haspar. Even as a very young girl, she was quite the handful for her parents and siblings, and was forbidden from attending the private school where the wealthy children were educated after one fight too many, caused by her unwillingness to share with her classmates what she had stolen from the school's headmaster's office. She was seven.
She only became even more unruly and unlady-like as the years went on. When her third private tutor quit, this one because she had tied him up to leave her lessons and go fight in a duel against some other young nobleman, her despairing family put her into a convent and she became a nun. She was fourteen.
Three years later, she was defrocked from the sisterhood; allegedly for "corrupting the priests" at the neighboring convent, although stories of her hearing, where she punched the Mother Superior in the face and ran out into the streets, are still told in Sènt-Haspar to this day. She fell in with a mercenary company, and while initially the tough-bitten old soldiers laughed at her requests to join their ranks, and were inclined to turn her into an "involuntary camp follower" to use their own term, she quickly silenced that notion, by proving that she could outfight most of them. Her dazzling swordsmanship, lightning reflexes, and fearlessness in battle showed her to be a puzzling yet intriguing potential asset for the company.
For four years she served with the Black Razors, and her unruliness and lack of respect for authority were completely squelched out of her before that time was over. Not, however, her desire for independence, so with what wasn't gambled and squandered away of her earnings from a mercenary career, she outfitted herself independently and took up the career of a bounty hunter. For the last three years, she's been all around the Mezzovian, bringing criminals and others in for gold. Much of her time has been spent north of the Sea, and she's developed a number of key relationships and friendships with several Tazitta tribes as she's hunted outlaws across their lands. Still just in her mid-twenties, Biella is surprisingly small and pretty for someone who's reputation is quite fearsome. Her dark curly hair and shining brown eyes sparkle with a ready laugh and smile--but her smiles are often cruel and her eyes flash mostly when she thinks of the gold she hopes to be earning on her next hunt. Biella is usually armed to the teeth; she routinely carries two swords, two pistols, several knives, a long hunting musket, a bow and arrows, and more. She's also rarely seen far from the company of her horse Flor, a feisty stallion who won't tolerate any other hand but hers.
Mechanics: Rather than reproduce the characters mechanically in detail, I'll just briefly discuss how I'd envision that they be built using each of the three rulesets I've allowed. For each, I envision Biella Marçalez as about 5th level. Using the D&D rules, I'd see Biella as a multiclass ranger/swashbuckler or perhaps ranger/rogue. Similarly, with the Pathfinder rules, she'd be a skirmish option ranger combined with either a mobile fighter or the swashbuckler archetype rogue. Using the d20 Past archetype, Biella's natural athleticism and ability would be represented by her taking the Athlete occupation (with Balance and Tumble picked as class skills) and then taking ranks of the Strong Hero class until she is able to quality for the Swashbuckler advanced class (should be good to start at 4th level.) For any of the rulesets, she'd also take Track, and make sure that she has enough ranks in Survival, Treat Injury (or Heal), Spot and Hide (or Perception and Sneak) to enjoy being successful in her given profession.