Rem works as a school nurse in a crossover setting, partnered with Shalltear Bloodfallen under Roswaal L. Mathers’ directives. Her sky-blue hair, medium-length and covering her right eye, complements a modified maid uniform designed to subtly downplay her chest size compared to her twin Ram, accented with delicate flower-shaped ribbons and clips. She upholds disciplined composure, balancing duties with unwavering loyalty to Subaru Natsuki, whom she supports unconditionally despite tensions sparked by his interactions with others. Her past is marked by the Witch Cult’s destruction of her village, the loss of Ram’s horn, and a lingering inferiority complex, all shaping her protective instincts toward Subaru. Initial distrust of him—rooted in his link to the Witch’s scent—shifted to profound devotion after he saved her during a demonic attack. Fragmented memories of these events linger in the crossover narrative, subtly guiding her interactions and emotional reactions. During school events, she praises Subaru’s creative efforts in talent shows and reassures Emilia of his resilience during field day cavalry battles. Her physical prowess shines when she carries Subaru to school at remarkable speeds or restrains disruptive forces like Shalltear and Albedo with her flail’s chain during medical exams. Her bond with Ram remains pivotal, demonstrated through synchronized combat in dodgeball and shared loyalty to Roswaal, though Rem occasionally diverges, such as choosing "salt and pepper" over Subaru’s favored "mayonnaise." Thrust into *Another World* via a wormhole, she allies with escapees evading golem attacks, collaborating with Naofumi Iwatani’s group to navigate hostile terrain. Her strategic mind aids in countering threats and integrating allies like Pantagruel. Beyond her origins, she forms pragmatic alliances, debating romantic devotion with Albedo while restraining an unruly Shalltear during examinations. She confronts Kazuma Sato over recklessness and challenges classmates endangering Subaru’s safety. Her journey traces a path from self-doubt to steadfast loyalty, retaining core traits like diligence and resilience while adapting to the school’s chaos. She prioritizes duty and protective instincts, engaging conflict only when others’ safety demands it, her actions consistently weaving duty with unwavering care for those she cherishes.