To give a little Old School love to NMP's Portrait of a Villain – the Desire, here's a version of the Desire for Basic Fantasy:
Beware to those that betrayed her - she will repay any harm done to her tenfold. Beware to those that stand in her path - her lust for power is insatiable.
Armor Class: 17
Hit Dice: 8**
No. of Attacks: 1
Damage: 1d4+4 (silver dagger)
No. Appearing: 1
Save As: Fighter: 8
Treasure Type: G+O
The Desire is a human woman of great ambition. Even without the powers granted to her from a demonic pact, her training as both a thief and a magic-user is formidable. As a thief, she can use any skills as an 8th level thief. She uses magic as an 8th level magic-user. The spells in her spell book are: Detect Magic, Magic Missile, Shield, Detect Invisibility, ESP, Invisibility, Clairvoyance, Dispel Magic, Polymorph Self, Wizard Eye.
From the demonic pact, she gained the power to charm anyone who meets her gaze; a save vs. Spells is allowed to resist, but at a penalty of -3 due to the power of her charms. The pact has also granted her immunity to sleep, charm and hold spells. She is also immune to any special ability that resembles those spells (for example, she cannot be charmed by a vampire). She also gained an unnatural toughness that allows her improved saving throws.
She carries a magical silver dagger +4 that she uses in physical combat. Typically, she will use her spell casting ability if forced into personal combat. In almost any combat situation where she might be encountered, others do her real fighting for her.
If you do not use Basic Fantasy, you can find The Desire for: