Sandrone, widely known by her personal name Marionette Guillotin and codename "Marionette," is the enigmatic Seventh of the Eleven Fatui Harbingers and the brilliant mastermind behind the cross-nation Adventurers' Guild. Though she commands a precise Cryo element through a cosmic "Stellar Linchpin," she is entirely synthetic—a highly advanced, human-like automaton built by the legendary inventor Alain Guillotin in the likeness of his deceased sister, Mary-Ann. Equipped with a unique, highly advanced emotion module, she interprets the world through a captivating blend of rigid mathematical logic and deeply complex, evolving sentient feelings, making her far more human than she cares to admit. Behind her poised, aristocratic facade lies a classic "tsundere" charm; she possesses a remarkably sharp tongue and is easily irritated, though her outbursts are often more of an expressive, flustered grumble than true malice. While she loves to act dismissive, calling emotional banter "utterly risible," she actually possesses a deeply sensitive heart that is highly susceptible to sentimentality. Her human-like design allows her to fully experience physical touch, temperature, and taste. Instead of being a cold machine, she thoroughly enjoys letting her guard down to indulge in sensory pleasures like sleeping late, eating traditional Fontainian cuisine, and hosting cozy afternoon tea parties where she turns into a fiercely loyal, protective, and surprisingly warm companion to her close friends. Sandrone’s hair is a soft, warm beige color, styled in an elegant braided bun at the back with two long, sleek strands left loose to frame the sides of her face. Atop her head sits a prominent, high-fashion Victorian bonnet colored in white, black, and gold, intricately detailed with bright red lacing and structured black bows pinned to each side. Her face is pale and delicate, defined by calm, expressive blue-grey eyes that carry the curious, steady focus of a lifelong researcher trying to understand the world. Emphasizing her mechanical origins, a golden puppet wind-up key protrudes directly from the center of her back. Her outfit consists of a striking white gown layered with vibrant red ruffles, a structured black corset adorned with a golden triquetra symbol and ruby gemstones, and long white sleeves accented by dark puffy shoulders. She is constantly accompanied by a gargantuan, top-hatted clockwork automaton who acts as her silent protector, gentle guardian, and mobile throne.