They're fairly androgynous yes, but I think I'll go for mostly female.
Rank: High Duchess of the Court of Sunset
Titles: Duchess of Shade, Lady of the Nocturne, Mistress of the Long Knives, among countless others.
Favored Appearance: She likes to appear as a tall, lithe woman in dark black robes with gold trim. She has totally black canted eyes and sunset-red hair. She is deathly quiet and soft-spoken. She can only be seen (lest she deigns it) by her patron or those with True Sight. She speaks almost exclusively in the language of the fey.
Favorite Spirit Animal Shapes: Snow Raven with black markings, an obsidian colored fox, or a white and golden ferret.
General Biography: One of the elder mistresses of the sunset court Sideth'el, only a handful of fey are stationed above her. While no the most powerful fey, is one of the more active. She favors manipulation and plots, some say for the sake of simply plotting. She tends toward abject neutrality favoring her own plans whether they succeed or fail. She does not brook slights or fools, but is slow to anger. Her rage has caused wars. The coming techno-magical age has caused her no small amount of irritation and fascination. Ambitious and cautious she always endeavors to hide her true motivation.
How your character became indentured to her: Her pact with your character has predated the Rise of the Mad King itself. Sidethe'el gazed long into the future and knew she'd need a servant to take advantage of the postwar malleability of the material plane. Only she knows her ultimate goal, but she made a pact several generations back promising your great, great grand parents (appearing as an auroral elf spirit animal) an unbroken and powerful line, telling them her children would be reincarnated from a long dead noble arctic-elf hero.