Ericht Samaya emerges as a four-year-old residing with her parents, Elnora and Nadim Samaya, at the Vanadis Institute's Fólkvangr research facility. Her early demeanor displays cheerfulness, curiosity, and naïveté; she frequently explores the facility and befriends staff. Ericht develops a significant bond with the prototype mobile suit XGF-02 Gundam Lfrith, viewing it as a sibling. On her fourth birthday, during an attack, she unknowingly activates the Lfrith's weapons system, destroying enemy mobile suits while mistaking the explosions for birthday candles. This event culminates in her father's sacrificial death as he sings "Happy Birthday," a memory leaving a lasting impact. Ericht and Elnora subsequently flee to Mercury. Space habitation strains Ericht's body, causing deterioration. To preserve her life, her biometric code synchronizes with the Lfrith's data storm, transferring her consciousness into the mobile suit, now designated XVX-016 Gundam Aerial. The Aerial becomes her new body. Conscious within the Aerial, Ericht matures yet remains committed to Elnora's (now using the alias Prospera Mercury) revenge against Delling Rembran and the Benerit Group. She actively supports these goals, employing force against obstacles. Despite this loyalty, she forms a protective attachment to Suletta Mercury, a repli-child cloned from her genetic material. Ericht communicates with Suletta through the Aerial's cockpit, offering comfort during doubt while striving to shield Suletta from the violent aspects of Prospera's plans. In conflicts like the Rumble Ring incident and terrorist attacks involving Dawn of Fold pilots Sophie Pulone and Norea Du Noc, Ericht uses the Aerial to generate overwhelming data storms, resulting in Sophie's death. She justifies these actions to Suletta as necessary for protecting the school and friends. Later, during Suletta's duel with Guel Jeturk, Ericht apologizes before Prospera initiates the Aerial's shutdown, causing Suletta's first loss. A pivotal moment occurs when Ericht severs ties with Suletta. She raises the Aerial's Permet Score to 8, subjecting Suletta to a data storm to reveal their origins: Ericht exists within the Aerial, and Suletta is her clone. Ericht states Suletta is no longer needed and ejects her, asserting that clinging to her or Prospera is impossible. She then fully aligns with Prospera for the next phase. Ericht participates directly in escalating conflict. She and Prospera travel to Quinharbor under Miorine Rembran's delegation, activating a permet field to instigate fighting between Earthian and Spacian forces. They subsequently destroy an Ochs Earth facility housing Gundam prototypes. Their actions lead them to Quiet Zero. Ericht, within the Aerial, connects to Quiet Zero and activates Gundnodes to annihilate the Space Assembly League fleet. Confrontation arises when Suletta arrives piloting the Gundam Calibarn. Ericht engages her sister in battle, leveraging GUND-Bits. Recognizing Suletta's resolve, Ericht attempts to target Miorine and allies infiltrating Quiet Zero. Her connection to the Gundnodes is disrupted before she can eliminate them. Three years after Quiet Zero, Ericht's consciousness persists within Suletta's "Hot" keychain, enabling communication primarily with Miorine. Their interactions involve frequent bickering, reflecting a sister-in-law dynamic. The exact mechanism of her survival within the keychain remains unexplained, though Ericht attributes it to Suletta's wish during the dissolution of the Gundams.