Ais Wallenstein operates as a first-class adventurer and executive member of Orario's Loki Familia. Renowned among the strongest adventurers, she bears the alias "Sword Princess" and has declined over a thousand courtship proposals. Her appearance features long golden-blonde hair, gold eyes, and a slender physique. She dons white and black battle attire with armored segments for dungeon expeditions, shifting to a white one-piece dress with gold lining during leisure. Her past centers on childhood trauma from the One Eyed Black Dragon’s assault, which obliterated her home and killed her mother. This ignited an all-consuming quest for vengeance, driving her to amass strength capable of slaying the dragon and reclaiming her mother. At age seven, she enlisted in the Loki Familia, starting as a supporter before rapidly ascending as an adventurer. She achieved Level 2 within a year—a record later eclipsed by Bell Cranel—and accelerated through ranks, reaching Level 6 after soloing the 37th floor’s Floor Boss. Ais displays a reserved demeanor, often seeming mysterious or detached due to muted emotional expression. Internally, she visualizes a younger self during vulnerability, retaining childlike simplicity. Despite her power, she refrains from disparaging weaker adventurers. Early fixation on revenge fueled self-destructive aggression, defiance of authority, and reckless combat disregard, earning her the "Doll Princess" epithet. Mentorship from Loki Familia executives Finn, Riveria, and Gareth gradually instilled balance, teaching mental resilience, technique, and rest alongside physical training. Yet her core hatred for monsters lingers, erupting when the Black Dragon surfaces or her Avenger skill triggers, clouding rationality. In combat, her Level 6 capabilities dwarf lesser adventurers, demonstrated by shattering adamantite and overwhelming foes like Revis. She commands Ariel, a wind-based enchantment hailed as "Great Spirit’s wind," shielding against toxins and generating barriers. Her Avenger skill massively amplifies attacks against monsters—especially dragons—intensifying with hatred to damage ordinary weapons. Additional Development Abilities include Hunter (boosting effectiveness against known monsters), Abnormal Resistance, Swordsman, and Spirit Healing (auto-replenishing mental stamina post-magic). Ais shares a complex dynamic with Bell Cranel, whom she rescued from a minotaur. Initially intrigued by his rabbit-like appearance, she mentors him through sparring, evoking rare happiness. She accepts his invitations for activities like dancing despite inexperience. Their bond fractures her worldview during the Xenos incident, where Bell’s defense of the monster girl Wiene challenges her extermination dogma. Witnessing monsters exhibit human emotions and hearts forces her to conclude she must personally judge what defines a monster. Her evolution includes shifting perspectives: revenge initially barred her from aiding Bell in the Great Faction War, fearing it would "rot" her "sword," but Xenos exposure and training with Ottar reshape her philosophy. She acknowledges hatred cannot solely guide her path, though obsession with the Black Dragon endures. Quirks involve aquaphobia from childhood "swimming training" with Riveria’s adamantite weights and gullibility toward Loki’s fabricated combat advice. Her growth entails reconciling trauma with new bonds. She guards her past closely, confiding only in Loki and top executives, and reacts violently when figures like Revis reference it. Her journey shifts from solitary vengeance toward nuanced strength and morality, while the drive to destroy the Black Dragon remains unyielding.