Chloe von Einzbern, known as Kuro, emerged as a separate personality formed from Illyasviel von Einzbern's sealed memories and faculties. Irisviel von Einzbern sealed these memories shortly after Illya's birth, enabling a normal life after the Fuyuki Holy Grail War system was abandoned. This sealed aspect developed independently within Illya over time. Chloe gained physical form by utilizing the power of the Archer-class Servant card containing the heroic spirit EMIYA, a future alternate timeline version of her brother Shirou Emiya. Initially identifying as Illyasviel, she adopted the name Chloe von Einzbern (Kuro, meaning "Black") to prevent confusion. Physically resembling Illya, Chloe displays distinct traits: tanned skin, white hair often styled differently, and light auburn eyes. She typically wears a modified feminine version of EMIYA's combat attire or a school uniform, appearing as a "palette swap" of Illya. Chloe's personality contrasts sharply with Illya's, presenting as calmer, more manipulative, and unrestrained, leveraging her perception of others' subtleties for advantage. Profound bitterness toward her parents for sealing her existence and toward Illya for desiring a "normal" life—interpreted as rejecting her purpose as the Grail vessel—fueled her initial attempts to eliminate Illya. She asserted sole right to the name "Illyasviel" and rejected labels like "secondhand clone." A magical seal linking her sensations to Illya's, causing shared pain if either was harmed, forced an uneasy truce. Chloe enrolled in Illya's school as her cousin, though conflicts persisted, often escalating into magical confrontations or comedic misunderstandings due to Chloe's need to drain magical energy through kissing. A pivotal shift occurred when Irisviel explained Chloe's origin as Illya's repressed Grail-related identity. Chloe expressed devastation upon learning the Holy Grail War no longer existed, leaving her without purpose. As she began dissipating from mana depletion, Illya shared her mana and urged Chloe to define her own wish. Chloe admitted her deepest desire was to have a family and live meaningfully. This genuine wish activated her latent Grail capabilities, stabilizing her form. Irisviel formally adopted her into the Einzbern family, introducing her to Shirou as Illya's cousin. Following integration, Chloe retained her mischievous and forthright demeanor but evolved into one of Illya's staunchest allies. She demonstrated fierce loyalty, prioritizing her friend Miyu Edelfelt over abstract ideals like "saving the world." Her relationship with Illya shifted from hostility to supportive rivalry, though they continued to bicker over minor issues. Chloe openly expressed affection toward Shirou, contrasting with Illya's reservedness, and exhibited jubilation upon discovering EMIYA's identity as Shirou's future counterpart. As a pseudo-Servant, Chloe's abilities derive from the Archer-class card. Her Noble Phantasm, *Kakuyoku Sanren: Triple-Linked Crane Wings*, replicates EMIYA's technique using projected swords Kanshou and Bakuya, enhanced by her teleportation capability. Her skills include Projection Magecraft (B-rank), Mind's Eye (False) (B-rank), Kiss Demon (B/B++-rank), Magic Resistance (C), and Independent Action (C). Her parameters are Strength (D), Endurance (C), Agility (B), Mana (C), Luck (C), and Noble Phantasm (C). In later events, including interdimensional conflicts, Chloe collaborated with Illya, Miyu, and allies like Gilgamesh to rescue Miyu from the Ainsworth family. She participated in beach trips, hot springs outings, and school festivals, gradually embracing ordinary experiences while maintaining her characteristic boldness and loyalty.