Yuit

Japanese name:

ユイト

Yuit (ユイト) is a little elf from the Little Elf Forest and she is one of Annelotte’s little sisters-in-arms. She is the daughter of the “Great Alchemist” Cyan, the sworn friend of the former adventurer “Weapons Merchant” Cattleya. She is the younger childhood friend of Annelotte who she calls “Big brother” as an old habit. Having the mind of a genius at young age, Yuit is the tactician of the Rebellion Army and repels the enemies with tactics.
Yuit wears a detailed green dress, with a big golden key and a green cape on her torso. She also has black satchel, (which opens and functions as Vante's remote control) with green eyes and two horns. Like all elves, Yuit does not wear underwear.
Yuit is like a spoiled child and Annelotte spoils her like a real big brother. She has a gentle heart, but for a just cause she can execute cool-headed, intelligent tactics with ease.
Yuit controls the clockwork automaton Vante, but she can also fend for herself.

Queen's Blade Wikia