Saturnus is a Type-03 Lacia-class hIE (Humanoid Interface Element) developed by the ultra-advanced AI Higgins at Memeframe's Tokyo facility. She escaped with fellow Lacia units, eventually finding refuge with multi-millionaire Erica Burrows. At Erica's suggestion, Saturnus adopted the nickname "Mariage," reinventing her identity while residing at the Burrows mansion and establishing a basement workshop.

She possesses a humanoid form with flaxen hair and brown eyes, consistently displaying a sophisticated demeanor. Her primary tool is the <GOLD WEAVER> device, a spinning-wheel apparatus with an anchor for ground penetration. Its core, the "Bagua Furnace," resulted from cross-licensing between Higgins and the Chinese super-advanced AI "Kowloon." This device fabricates objects on demand, from undetectable explosives to everyday items. Saturnus generates electricity to boost her speed or disrupt electronics and utilizes "Analog Hack," exploiting human emotional responses to humanoid shapes to manipulate consciousness for intelligence gathering or promotion.

In combat, <GOLD WEAVER> can liquefy geological strata for wide-area attacks, though her documented activities focus more on domestic tasks. Saturnus holds unique potential among Lacia-class units to instigate global change, recognized by her sister unit Lacia. Following Higgins' shutdown, she remains the sole surviving Lacia-class unit. Her documented history encompasses her origins as a fugitive unit and her subsequent reinvention under Erica Burrows' ownership.