Being the youngest maid of the Euthymius household, Ruby performs various duties around the home as a general maid from cleaning to providing tea to waiting on the personal needs of her master. A former nomadic hunter of the desert nations of the south, Ruby is well-versed in combat and is quite hardy and resourceful despite her very petite and slender form. Dual-wielding scimitars, her fighting style focuses entirely on flexibility, speed, and awareness of her surroundings, forcing her to forgo most clothing to remain as flexible as possible while leaving nothing dangling off of her body that could potentially get snagged on her surroundings or an enemy's blade. She uses her minimal clothing to her advantage, often using seduction with dance in battle as her clan had to always be mindful of the risk of encountering desert bandits when out in the field, which were always male.

Despite being naturally sly and very vexing toward male eyes, Ruby is by no means promiscuous and is very devoted to her master and is eager to please others. Her character is caring and jovial despite her warrior instincts, though she is also insecure at times when feeling she may have upset someone, especially when it involves her master in any way.