I've written her backstory as if in the Forgotten Realms setting. I'm not trying to say we 'should' do that, it just tends to get my creative juices flowing (have DMed, read novels, and played games like Baldur's Gate, in FR). It'd be trivial to substitute or edit out the proper nouns for whatever setting.
WotC-style plaintext stat block for now, will happily do mythweavers or other desired format though.
Will think of magic items later. If DM allows, might be interested in a 'pounce' item, which incidentally is a nice example of the aforementioned magic item price formulae.
Pounce is a druid spell (Complete Divine) that allows a full attack at the end of a charge, i.e. it's a buff spell. It's a first level spell,and lasts 1 round / level (multiplier = 4), so continuous price would default to 2,000 x 1 x 1 x 4 = 8000 gp.
If this is allowed, will probably just do this and defensive items to get up to 15K (like +1 armor and a +2 resistance item).
For a minor custom/heirloom item of the sort Nicci suggests, maybe something with a Hide bonus, or which casts Invisibility a few times a day.
Class: Rogue / Swashbuckler
Bio: Daughter to retired adventurers who'd more or less bought their way into polite Luskan society using the treasures, skills, and reputations gleaned from their exploits, Aria grew to found herself nudged towards high learning. Her parents, it seems, hoped for a safer life for their daughter, and to their dismay her favorite subject seemed to be her fencing practice nonetheless. At least, unlike most of her friends' parents, her own seemed amenable to the idea of a daughter learning such things at all, perhaps because their careers had shown them what a dangerous place the world could be.
These teenage tensions boiled over into Aria learning how to sneak out and about at night, and she got herself into tatters of trouble, and eventually one scrap she'd not have survived from herself. Rescued from petty thugs of a Luskan pirate lord by a priestess of the Red Knight, Aria ventured out to visit her savior's temple on subsequent nights. She never lost her disobedient urge, but perhaps channeled it with more purpose.
She found companionship and learning of the sorts she'd longed for, which proved a bulwark against a dark part of her own nature: she discovered through the aggravating throes of puberty, and leafing about in her family heraldry, that one of her great-grandmothers just might've been an erinyes devil. This shared revelation renewed her priestess benefactor's attentions and concerns. So far, Aria has maintained a far loftier heart than her infamous ancestor's. The blood may've even contributed a disciplined and logical bent of mind which serves well one who would revere the Lady of Strategy.
(Will provide more of a 'coda' to backstory when I have a better sense of the RP's opening location/scene, i.e. why and how she got there.)
Aria, lesser tiefling, gestalt rogue 6 swashbuckler 6
Medium Outsider (native)
Hit Dice: 6d10+12 (49 hp)
Speed: 30 ft.
Armor Class: 19 (+5 Dex, +4 armor), touch 15, flat-footed 14
Base Attack/Grapple: +6/+9
Attack: kukri +12 melee (1d4+6/15-20) or comp. longbow +12 ranged (1d8+6/x3)
Full Attack: two kukris +10/+5 melee (1d4+6/15-20) or comp. longbow +12 ranged (1d8+6/x3)
Space/Reach: 5 ft./5 ft.
Special Attacks: insightful strike, lesser darkness 1/day, sneak attack +6d6
Special Qualities: darkvision 60', dodge bonus +2, evasion, grace +2, resistances (cold, elec, fire 2), trapfinding, trap sense +2, uncanny dodge
Saves: Fort +4, Reflex +12, Will +3
Abilities: Str 16, Dex 21, Con 14, Int 16, Wis 13, Cha 9
Skills: Bluff +10, Disable Device +12, Hide +16, Listen +10, Move Silently +14, Open Lock +14, Search +12, Spot +10, Tumble +14
Feats: Daring Outlaw, Improved Critical (kukri), Improved Two-Weapon Fighting, Telling Blow, Two-Weapon Fighting, Weapon Finesse
Alignment: Lawful good
Deity: Red Knight ('The Lady of Strategy', LN goddess of tactical and wisdom warfare) if Forgotten Realms setting; or closest analog of Athena if in another setting
Flaws: Frail (-1 hp/level), Weak Fortitude (-3 Fort)
Languages: Common, Draconic, Elven, Infernal, Sylvan
Possession: two mw kukris, mw comp. longbow (Str rating +2), mw chain shirt, quiver with 100 cold iron arrows and 20 silver arrows, 2 kukris, 2 throwing axes, 2 light hammers, 6 daggers, grappling hook and 100' of silk rope, thin bedroll and rain tarp, one tenday of rations, flint and tinder, 3 sunrods, two scout's outfits, one silk aristocratic gown, forest camouflage rain cloak (mw tool for hide), soft padded elven footwear (mw tool for move silently), map of the known world, canteen, light warhorse and military saddle, 100 gp
Darkvision (Ex): A tiefling has darkvision to a 60-foot range.
Lesser Darkness (Sp): Once per day, the tiefling may use an effect similar to darkness (caster level equals tiefling's character level), except that the radius is 5 feet. This ability is the equivalent of a 1st-level spell.
Skill Bonuses: A tiefling has a +2 racial bonus on Bluff and Hide checks.
Resistances (Ex): A tiefling starts play with resistance 2 to cold, electricity, and fire.
Insightful Strike (Ex): add Int mod to damage with light and finessable weapons.
Telling Blow (Ex): add sneak attack damage to critical hits.
Sources: Complete Warrior: swashbuckler; Complete Scoundrel: Daring Outlaw feat (stack rogue and swashbuckler levels for determining dodge, grace, sneak attack); PHBII: Telling Blow feat (crits deal sneak attack damage); Savage Progressions (Wizards site): lesser tiefling (i.e. LA +0 tiefling)