Chloe Aubert arrived in the Central World as a Summoned Otherworlder through a dimensional crack with Leon Cromwell, who became her surrogate older brother. Rituals by Western nations immediately separated them, summoning her to the present era. Unable to manifest a Unique Skill, she faced fatal magicule overflow and entered Freedom Academy alongside similarly afflicted children: Kenya Misaki, Ryota Sekiguchi, Gale Gibson, and Alice Rondo. Initially taught by the retired adventurer Shizu, the class transferred to Rimuru Tempest's care after Shizu's death. During spiritual training in the Dwelling of the Elementals, Chloe stabilized her magicules and averted death by merging with her future self's spiritual body instead of bonding with an elemental. Rimuru later entrusted her with the Anti-magic Mask and gifted her new clothing before her permanent relocation to Tempest. As a child, she possessed waist-length black hair, blue eyes, and wore a simple pink frock with a black student cloak. As an adult demi-god, her attire evolved: a white cape dress layered over a long-sleeved black shirt, a black corset, a black waist cape, white gloves with a left-hand gauntlet, white-and-blue boots, black spats, and a ruby necklace. Her black hair was styled in a side ponytail, retaining delicate facial features. During heroic activities, she concealed her identity with the Anti-magic Mask, limiting public recognition. Personality-wise, she displayed introversion, preferring picture books and manga. Often stoic, she was capable of deep emotion. Repeated time travels to protect loved ones forged exceptional determination and resilience. In battle, she executed enemies with ruthless efficiency. She developed romantic feelings for Rimuru, initiating kisses and adopting a mature demeanor around him. Trusted by diverse figures—from humans to demons—she operated discreetly under aliases like "Chronoa," rarely disclosing her time abilities. Her capabilities specialized in time manipulation. Key skills included "Time Traveler," activating during traumatic events like Hinata Sakaguchi's death, transporting her 2,000 years into the past. There, she awakened the "Hero's Egg" and transferred it to her younger self, creating a stabilizing temporal loop. As the legendary Masked Hero, she imprisoned the Storm Dragon Veldora using the Unique Skill "Infinity Prison" after confronting him during his attack on a human city. This act indirectly facilitated Rimuru's encounter with Veldora and influenced broader geopolitical alliances. Her chronological development involved intersecting timelines. During spiritual training, her future self manifested, attempted to kiss Rimuru, and merged with her. Later, under Yuuki Kagurazaka's control via the skill "The Order of Three," she killed Hinata, merged with her consciousness, and traveled to the past. After Hinata's separation and revival, Chloe infiltrated Yuuki's operations, subtly subverting his commands—such as healing his knight Claude to free him from mind control. Following Yuuki's assassination and subsequent revival order, she dueled Rimuru to a draw and fought Guy Crimson under compulsion. During this conflict, she merged with the Manas Chronoa to break Yuuki's control, gained the Ultimate Skill "Hope King Sariel," and eliminated the invading Manas Lucia. Post-conflict, she joined the coalition against Velda and later shared a peaceful moment with Rimuru.