Meili Portroute (メィリィ・ポートルート) is a Demon Beast tamer and former member of the Assassin Organization. First introduced in Arc 2 as a hidden antagonist, she is the main antagonist of Arc 4 alongside Elsa. After the events of the arc, she joins the main cast and later serves as one of the main supporting characters of Arc 6.
Introduced as an inhabitant of Irlam Village, she is later revealed to have been behind the Demon Beast attack in Arc 2. In Arc 4, she and Elsa are hired to attack Roswaal's Mansion, but she surrenders after Elsa is killed. In Arc 6, she accompanies Subaru and his companions to the Pleiades Watchtower while intending to avenge Elsa, but ultimately gives up on it and joins the Emilia Camp.
Meili Portroute had refined yellow-green eyes that gave off an air of mysticism and an equalled well-formed nose. Her long dark-blue hair was kept out of her face and tied into a triple-braid that flowed down to her hips. A pink flower ornament with white outlining similar to Elsa's framed the left side of her head. During her undercover stay in the village, Meili's braid traipsed over her left shoulder so that it rested over her chest and her hair wasn't decorated with an ornament. She looked the same age as Petra Leyte, suggesting she was around twelve to fourteen years old. When not concealing her true nature, Portroute gave off the foreboding impression of someone who would grow up to be a true demon.
The outfit Meili commonly wore was befitting of a girl of her moral character. Her ensemble consisted of a long-sleeved black one-piece dress with a frilly white hem and white cone-shaped cuffs, brown tights with vertical-facing lighter brown stripes, a white cravat, and a pair of black boots that had cuffs with purple feathery-trimming along their edge. Her dress had a black collar and reached past her hips. Like Elsa, she wore a long purple-brown cloak that reached down to her ankles and had purple trimmings, although unlike Elsa's cloak, Meili's had a golden pendant serving as a strap and no hood. When she was undercover as a villager, Meili wore a short blue long-sleeved one-piece dress with a flap collar similar to a sailor's. On her feet she wore a pair of brown sandals, and a part from these and the dress, Meili wore no further clothing as a village.
When she was born, she was a feral child and did not know how to talk at all. She was raised by Demon Beasts and was taught how to survive through them. When Elsa brought Meili to the Assassin Organization, Meili started to admire her and began learning how to live like Elsa. Elsa taught her the basics of life and she started to become her purpose to live.
When she was first introduced, Meili acted like she was shy and meek, though in actuality she is extremely friendly and familiar toward others, even toward her targets. She also has a habit of stretching out the end of her sentences. During her stay at the Pleiades Watchtower, Meili becomes attached to Shaula, who she refers to as "naked onee-san", and typically spends her time hanging on to her shoulder.
But Meili failed to display any semblance of the childish innocence usually exhibited by those her age. She was perfectly willing to kill people, regardless of whether they were innocent or children like herself. She also had a penchant for deception well beyond her years, such as when she was able to mimic the behaviour of a regular child. Meili's village girl persona was meek. She didn't talk much or interact with Subaru as much as the other village children, although she always joined in on the fun and laughed when they did. The only time she was the center of attention was when she showed Natsuki and the children the disguised Demon Beasts. When asking Subaru to come see the Demon Beasts, she acted overly-polite and timid, stuttering as she spoke.
Despite originally being a member of the same organization as Elsa, Meili asks the Emilia Camp to protect her following her defeat, as she feared that she would get purged for failing her mission and losing Elsa.
Meili Portroute was born with a powerful Divine Protection that allowed her to manipulate the behaviour of man-eating predators known as Demon Beasts. She was abandoned by her parents and subsequently grew in the wilderness surrounded by Demon Beasts that protected her. As a result, Meili was a feral child incapable of basic speech and etiquette. One day, an assassin known as the Bowel Hunter, real name Elsa Granhiert, appeared before Portroute and killed the beasts that protected her. The feral girl was abducted by Elsa who inducted her into her organization—the Gusteko Assassin Organization.
Portroute was taught many things by Elsa, including how to talk and behave properly. She quickly became an operative of the organization who used her control of Demon Beasts and deceptive youth to execute her targets. She was frequently paired up with Granhiert on missions, whom she considered an annoying older sister of sorts. Portroute, like most members of the organization, feared their leader known simply as "Mother." On one occasion Mother turned Portroute into a pile of frogs as an example of her power. She was particularly fond of a Demon Beasts belonging to the large and powerful Guiltylowe species that she considered a pet.
Divine Protection (加護 Kago): Meili has the Divine Protection of Magic Manipulation (魔操の加護 Masou no Kago), which allows her to control hornless Demon Beasts, making her a Demon Beast User (魔獣使い Majuu Tsukai). Normally, hornless Demon Beasts are killed by others, but due to her Divine Protection, she apparently functions as a horn. She is unable to control powerful Demon Beasts such as the Hakugei and can be incompatible with certain others, such as the Oiranguma, though she can still control them.
- Demon Beasts Control: Kurohebi and the Hakugei are completely immune to her control. There is presumably also a limit to the number of Demon Beasts she could control at one time though no exact numbers have been given.
Stealth Mastery: While she doesn't hold a candle to Elsa in terms of stealth mastery, Meili is still capable of erasing the sound of her footsteps.
Miasma Aura: Meili apparently emits a miasma like aura continuously, which is the reason why the Emilia Camp had to have her live underneath Roswaal's mansion. It is unknown whether this is because of her Divine Protection or not.
- She carries around a Reinhard doll Elsa made for her.
- She had a pet Gulitylowe, this same Demon beast saved Subaru from Reinhard in the Pride If Story.
- Erika Harlacher, Meili's English voice actress, also voices Duchess Crusch Karsten and Ram & Rem's mother Temae.
- It is implied that she may have a past connection to Dynas.
- Meili has her own named chapter in Arc 6, in both the Web and Light Novels.
- In the Web Novel, Meili originally had brown hair, until it was changed to dark blue in the middle of Arc 6.
- "We know about your hard work, Dynas. It wasn't your fault you couldn't protect Milan and Meili." Arc 5: Chapter 68. Section 1.
- "She had braided, brown hair, and simple, yet lovely facial features." Arc 6: Chapter 3. Section 1.
- "The little girl who had spoken out and lifted her tiny hand up had dark blue braided hair—Meili. She slowly shook her head, still perched on Shaula's shoulders (who had crumpled down to her knees fainted)." Arc 6: Chapter 27. Section 2.