Mare Bello Fiore, a dark elf crafted by Bukubukuchagama, serves as the Sixth Floor Guardian of the Great Tomb of Nazarick alongside his twin sister Aura Bella Fiora. His dark skin, pointed ears, golden hair, and heterochromia—a blue right eye and green left eye—define his appearance. Feminine features and specific attire, explicitly designed by his creator, frequently lead to his misidentification as a girl. This cross-dressing ensemble includes a blue dragon scale bodysuit, a white and gold vest bearing the Ainz Ooal Gown sigil, a forest-green leaf cloak, a short white skirt, an acorn necklace emitting silver light, white silk gloves, and a twisted black wooden staff. He exhibits a shy, stuttering, and submissive personality, often seeming cowardly in social situations—a marked contrast to Aura's energetic nature, reflecting their creator's design that the younger brother obeys the elder sister. Despite this outward timidity, Mare displays unwavering loyalty to Ainz Ooal Gown and executes duties or confronts threats to Nazarick with cold-blooded efficiency; some external observers note his meekness may seem performative. He prefers solitary pursuits like reading in the Ashurbanipal library or sleeping, avoids prolonged conversations with other residents such as Pulcinella, and possesses keen observational skills regarding his sister's moods. Mare collects plant species, differing from Aura's interest in beasts, and openly lavishes praise on Ainz. He exhibits extreme emotional dependence on Ainz's approval, becoming tearfully distraught when fearing failure or criticism and profoundly grateful for encouragement. Deeply reluctant to act independently without explicit permission from Ainz or his creator due to fear of reprimand, he will admonish Aura for inappropriate behavior towards other Guardians like Shalltear. Mare and Aura operate as a unit, required to inform each other of movements within Nazarick. Mare typically stations himself in the Sixth Floor's Amphitheater while Aura patrols the forest, reporting to her before leaving his post. During the Undead King Arc, intense fear in Ainz's presence initially prevented Mare from greeting him properly, requiring Aura's intervention. He participated reluctantly in a combat test against a Primal Fire Elemental summoned by Ainz, needing protection from Aura's dragonkin servants and attempting to flee before being forced to fight alongside his sister. Victory led Ainz to offer Mare water, easing his fear. Mare later suggested using earth and plants to camouflage Nazarick's exterior walls, a task Ainz assigned to both twins with permission to utilize resources from other floors. Following a meeting with other Guardians, Mare expressed fear of Ainz's Despair Aura and became flustered when Demiurge questioned him about breeding experiments for Nazarick's benefit; he agreed to assist if ordered by Ainz and confirmed his cross-dressing stemmed from his creator's design choices. Mare wields druidic magic specializing in earth manipulation and plant control, enabling terrain reshaping and camouflage generation. He recruited undead and golems to assist the Nazarick camouflage project. His combat abilities encompass large-scale destructive spells and potent support buffs for allies, capable of devastating entire areas. Ainz later rewarded Mare's efforts with a Ring of Ainz Ooal Gown, reinforcing Mare's promise to work harder for his master. No specific activities or development details exist for Mare Bello Fiore within the documented Isekai Quartet 2 media.