Ais Wallenstein, renowned as the Sword Princess, serves as a first-class adventurer and executive member of the Loki Familia in Orario. She is the reincarnation of Ariadne Lakrios, the former queen of Lakrios. Her appearance features long golden-blonde hair, gold eyes, and a slender build. She typically wears a white-and-black battle cloth, black arm covers, long blue boots, and armored components including a breastplate and knee guards. Outside the dungeon, she favors a simple white one-piece dress with gold lining. Characterized by quietness and difficulty expressing emotions verbally, she often appears mysterious or aloof. Despite this, she exhibits mental youthfulness, occasionally visualizing a younger version of herself in vulnerable moments. She possesses a strong-willed and determined nature, intensely focused on becoming stronger to achieve her goal: defeating the One-Eyed Black Dragon. This creature caused her parents' death during her childhood, fueling an almost irrational hatred of monsters and a revenge-driven obsession, though she does not look down on weaker adventurers. The trauma also instilled a fear of water due to a childhood punishment by Riveria involving adamantite weights, rendering her unable to swim. Joining the Loki Familia at age seven, she rapidly advanced to Level 2 within a year—a record later broken by Bell Cranel. She continued leveling at an exceptional pace, reaching Level 4 in approximately one to one-and-a-half years per level and achieving Level 6 after soloing the floor boss Udaeus on the 37th floor. Her combat prowess excels against monsters, though she faces acknowledged weaknesses in human combat compared to peers like Ottar. Her abilities include the wind-based enchantment magic Ariel, named after Shakespeare's air spirit. Ariel functions offensively and defensively, creating wind armor or shields; at full power, it manifests as a "fortress of wind" capable of overwhelming high-level adversaries. One technique, Lil Rafaga, involves a wind-enhanced lunge. Her Skills include Avenger, which amplifies attack power against monsters—especially dragon types—based on her hatred. Its severe output damages weapons and clouds her judgment, reverting her to a more volatile state. Her Development Abilities are Hunter (improved effectiveness against previously encountered monsters), Abnormal Resistance (nullifies poisons), Swordsman, and Spirit Healing (auto-regenerates mind after magic use). Her character development revolves around gradual emotional openness and reassessment of her worldview. Initially volatile and self-destructive as a youth—earning her the moniker "Doll Princess"—she tempered these tendencies under the mentorship of Finn (emphasizing mental fortitude and technique), Riveria (providing magical tutelage), and Gareth (instilling the importance of rest). Despite this growth, her core hatred persists, resurfacing when the One-Eyed Black Dragon is mentioned or when using Avenger. Interactions with Bell Cranel significantly influence her evolution. She first saves him from a minotaur, sparking his admiration. Intrigued by his rapid growth, she trains him, exhibiting uncharacteristic happiness during their sessions. She defends him from ridicule, tends to his injuries, and accepts his invitation to dance at the Apollo Familia ball—her first dance. During the Xenos incident, her rigid stance on monsters wavers after witnessing the monster girl Wiene protect Bell. This culminates in her accepting that some monsters possess human-like emotions, concluding that "monstrous" nature is defined by actions rather than origin—a realization solidified during training with Ottar. She maintains secrecy about her past, confiding only in Loki and the Loki Familia's top executives. Confrontations with figures like Revis, who referenced her history, caused severe emotional distress. Her commitment to defeating the dragon occasionally isolates her, such as refusing to aid Bell during the Great Faction War to avoid "rotting her sword" by wavering resolve. In the spin-off *Sword Oratoria*, her adventures with the Loki Familia are central, exploring investigative missions into dungeon anomalies and deepening bonds with comrades like Lefiya Viridis. The *Infinite Combate* game expands on her story through exclusive dungeon-crawling narratives and character interactions. Trivia notes include her rumored rejection of 1,000 suitors, a favorite food (Jagamarukun), and minimal dialogue (149 words) in the first anime season.