Meili Portroute wields a Divine Protection allowing manipulation of hornless witchbeasts, acting as their "horn" to exert control while they retain individual will. Creatures like the Hakugei remain immune to this influence. A continuous miasma aura necessitates her isolation beneath Roswaal Manor during imprisonment. Her stealth includes suppressed footsteps, though not matching Elsa Granhiert's mastery. Abandoned early, she was raised by witchbeasts in the wilderness, resulting in feral behavior and an inability to speak. Elsa Granhiert discovered her, killed her protective beasts, and noted the name "Meili" sewn into her rags. Elsa abducted her, teaching language, etiquette, and assassination skills, becoming a sister figure and Meili's primary purpose for living. Meili harbored deep fear of their leader "Mother," who once transformed her into frogs as punishment. She initially posed as a timid village girl with brown hair (later depicted as dark-blue), tied in a triple-braid over her shoulder, wearing a simple blue dress for camouflage. Her true appearance reveals refined yellow-green eyes, a pink flower hair ornament resembling Elsa's, and a signature outfit: a long-sleeved black dress with frilly white hem, brown striped tights, white cravat, and black boots featuring purple feather trimming. She often adds a purple-brown ankle-length cloak fastened by a golden pendant. This deceptive "shy villager" persona masked ruthless willingness to kill innocents and children, reflecting a lack of conventional morality. She displayed fondness for witchbeasts, considering them "cute" and avoiding their deaths when possible, cherishing a Guiltylowe as a pet and crafting sewn dolls. Following Elsa's death, confusion and unresolved grief drove her to attempt vengeance against Natsuki Subaru. Intervention and offers of support from Subaru and Emilia led her to gradually embrace a surrogate family role within the Emilia Camp, showing regret for past actions. Key missions include collaborating with Elsa in the Red Snowfall conflict prior to Arc 1, using a Guiltylowe to assassinate Igor Kenash. In Arc 2, she infiltrated Irlam village, luring Subaru into a Wolgarm trap. During Arc 4, she aided Elsa's assault on Roswaal Manor, deploying witchbeasts that destroyed the mansion across multiple timelines. Captured after Elsa's demise, she cooperated with her captors, fearing Mother's retribution. Post-imprisonment, she joined the Pleiades Watchtower expedition in Arc 6, utilizing her abilities to avoid demon beast encounters. She bonded with Shaula, nicknaming her "naked onee-san," and sought Elsa's memory book in the Taygeta library to comprehend grief and life's value. She later volunteered to relinquish her Divine Protection to aid Subaru's rescue, though Petra Leyte prevented this sacrifice. She developed rapport with Petra, listening to her complaints and expressing concern for her safety. By Arc 9, she serves as a supporting character within the Emilia Camp.