Alice Swayne endured a traumatic childhood under parents who abused substances. Her father forcibly addicted her to drugs and involved her in illegal activities from a young age, leveraging her dependency to facilitate his drug trade. After his death, she became a homeless addict, struggling to survive on the streets until Mikhail Renfred found her in an alley. Recognizing her latent magical potential, Renfred administered a painful elixir that cured her long-term withdrawal and freed her from addiction. He took her in as his apprentice, offering stability and purpose. Early in this period, Alice accidentally opened a cursed book, forcing Renfred to intervene and sacrifice his arm to save her life. In response, she vowed to become his guardian, an expression of loyalty and gratitude.

Alice initially acted antagonistically, notably during events in Ulthar where she pushed Chise Hatori into water and held her hostage while Renfred attempted to retrieve a magical blight. Her motivations shifted when Joseph (Cartaphilus) threatened Renfred's safety. Under duress, Alice attempted to capture Ruth, Chise's familiar, confessing to Chise that coercion was her only reason for compliance. When Joseph tried to kill Alice for revealing too much, Chise intercepted the attack, sustaining severe injuries. This sacrifice prompted Alice's shift from adversary to ally. After Renfred secured her release, Alice retaliated by shooting off Joseph's stolen arm.

Her appearance features wavy blonde hair, often tied back, and she typically wears practical coats or professional suits during missions. As part of a contract with a Will o' the Wisp, she later cut her hair to chin length, weaving it into a pouch containing a piece of coal. This change symbolized her deepening connection to fire-aligned magic. Her demeanor is characterized by blunt speech, determination, and a boyish manner of dress and behavior, though she identifies as female.

Alice's loyalty to Renfred remained a core aspect of her identity, driving her actions even as her relationship with Chise evolved into friendship. They bonded over shared experiences of traumatic pasts and rescue by mentor figures, collaborating on tasks like Christmas gift shopping for Renfred and participating in the London dragon auction retrieval. During efforts to rescue Chise from a later kidnapping, Alice fought chimeras summoned by Cartaphilus. Her magical affinity for fire attracted a Blue Flame entity, which requested to channel her power to disperse hostile wraiths. The entity found her soul "irresistible" due to its fire alignment and chose to remain with her as a companion.

Her development continued within the College arc, where she served as Chise's initial campus guide and attended classes. Overhearing Renfred describe her as his daughter rather than his guardian caused significant emotional distress, as she associated the term "daughter" with her abusive father. This revelation led her to seek solace with Chise, confiding frustrations about perceived weakness during Joseph's invasion of their home. She expressed a firm preference for the guardian role, later confronting Renfred to reaffirm this identity despite his paternal feelings.

Driven by a desire to strengthen her guardianship capabilities, Alice intensified her training regimen at the College, dedicating extensive time to combat practice and magical studies. Instructors noted her heightened focus, expressing concern about potential overexertion similar to past cases where students suffered magical repercussions. One instructor acknowledged her determination to "impress someone" and permitted increased resource access while cautioning against an unsustainable pace.

Her abilities include proficiency in magical theory, firearms, and knives, aligning with her guardian duties. She utilizes teleportation via enchanted tools provided by Renfred, targeting pre-set coordinates. Her fire-aligned magic, amplified through the Will o' the Wisp contract, enables potent offensive and defensive applications. This contractual bond also grants her additional magical reserves and versatility in spellcasting.