My wife put in a request for some of her favorites, but I figured I'd ring in an interesting Big Bad. (Sorry, love!)
The shenanigans that ensued wound up getting rolled into a plotline, and the party drew her ire when they busted up what she thought would be a permanent gig, forcing her to flee one step ahead of the authorities and leave behind her husband and daughter. Her pattern since has been to marry rich men, under a false identity, take them for what they're worth and split.
Feeling vengeful, Datia went to work and learned about the party. She supplied damaging information about the rogue's father to the rogue's mother, causing the breakup of their marriage. Her next target was the old alchemist on the corner who was a favorite of theirs, and in marrying and ditching him clipped a heap of gold and a bunch of high-powered alchemical poisons, which she used to great effect -- through cutouts -- in taking out or sickening several folks near and dear to them. On two other occasions, the trouble coming to the party was provoked by her, unbeknownst to them.
Datia's only significant magical item is a stolen religious relic of some power, much of which she can't use; the key power she can use is that it renders her immune to scrying or divinations. She's a good actress and deft at disguise. She also has some modest arcane powers, but no one outside of her estranged and embarrassed family remembers that she had a brief wizardly apprenticeship in her teens, and she never lets anyone know.
Beyond that, she’s smart and focused. She doesn't have a gang to betray her. She's very likeable, and folks trust her instinctively and talk freely in front of her. If she needs help, she'll beguile a fellow and wrap him around her fingertips, but she'll never let that fellow know where to find her, and she will always have a bolthole and a fast mount available. She won't let herself get suckered into a confrontation, direct or otherwise. She doesn't leave trademarks or mocking Ba-Ha-Ha notes. If a plan looks like it's blown, or she thinks a situation is spiraling outside her control, she'll cut her losses and bolt, and if possible has a secondary mark in hand to take the fall.
In short, she's read the Evil Overlord Rules.
RPG groups, by and large, suck at detective work. They rely heavily on their widgets and spells, and they count on the bad guys making predictable, cliched mistakes or having blatant, exploitable character flaws. They don't often do patient, and they can't often handle patient. A hundred times more of these scenarios end because the GM has placed a finite limit on them (and, of course, the PCs always win in the end, right?) or from the foregoing factors than not.
I was proud of her. It's easy for a GM to beat down a party with overwhelming force, zowie! powers like teleportation or insubstantiality, by a NPC's Epic Uberness, or by a torrent of widgets. Doing so with guile and misdirection, with a hard-keyed scenario (hey, if they had made all the right guesses and been a little lucky, she could have been nailed much sooner), that's harder.
What they never did attempt was to trap her at the only spots of vulnerability: (1) There's only a finite number of rich, single guys out there who get swept up by a beautiful, cultured woman from Somewhere Else and who loves the city life; and (2) She still had affection for her first husband and for her daughter. It took the main party nearly five real years to catch her, and in the end only because they called in some major favors and brought some immense arcane powers to bear.
ST: 9 DX: 11 IQ: 13 HT: 10 Speed: 5.25 Move: 5
Advantages: Acute Taste-Smell/1; Beautiful; Charisma/1; Comfortable wealth; Empathy; Magery (Body Control spells only)/2; Serendipity; Smooth Operator/2
Disadvantages: Callous; Greed; Minor Medical Ailment/migraines; Social Stigma: outlaw; Major Vow: Revenge!
Skills: Acting-15; Administration-13; Area Knowledge: Warwik royal demesne-15; Baseball-13; Body Language-14; Current Affairs/high society-15; Carousing-15; Connoisseur/music-13; Dancing-12; Detect Lies-14; Disguise-15; Erotic Art-14; Fast-Talk-15; Filch-13; Forgery-13; Holdout-13; Knife-12; Mimicry (human)-14; Musical Instrument / lute-11; Needlecraft-10; Observation-13; Poetry-12; Poisons-13; Savoir-Faire-16; Search-14; Sex Appeal-17; Vajikry-13
Grimoire: Arousal-13 †; Birth Control-13 †; Choke-15; Comfortable Seat-13 †; Fair Skin-14 †; Rapid Intoxication-13 †; Resist Intoxication-13 †; Resist Pain-13; Stun-15; Tears-15
Maneuvers: Ruse / w/Sex Appeal-16
Quirks: "But wealth IS power;" Attracted to "bad" men; Fashion slave; Overestimates her luck; Soft spot for animals & kids
Explanations: Serendipity means something just goes seriously right for you, once per adventure: a tree branch breaks over the head of the guy who's about to run you through, the first box you break open in the warehouse has the Ark of the Covenant, that sort of thing. Smooth Operator gives bonuses to social skills (which are figured in already) and you’re recognized as a suave person. Migraines? Make a HT roll every day. If she blows it, she’ll have about two hours worth of -2 to everything, at some point (she's taken too many alchemicals over the years, and the headaches are a side-effect). Yeah, they play baseball on my world, and it’s considered an avant-garde spectator sport in the capital. Vajikry is a game that's something of a cross between checkers and Stratego. Her Ruse maneuver basically drops a guy’s combat defenses by heavyweight vamping; letting her top fall open or off is a favorite.
I’ve invented a bunch of spells (well, a couple hundred of them); the ones marked † are the non-book ones. Comfortable Seat prevents saddlesores and jostling in carriages. Fair Skin keeps your complexion mild. The others are self-explanatory, and I’m quite narked that SJ Games saw fit to exclude a birth control spell, which you’d think would be one of the more fundamental spells in any realistic culture. If you prefer GURPS RAW, substitute others.
For further explanation of system stats, check this link.