Mil, an anime-original character from Hakum Village, serves as a Rider and companion to Lute, Cheval, Lilia, and Hyoro. She graduated from Hakum Village's Rider School alongside them, bonded with an Aptonoth as her first monstie, and initially displayed a serious, direct personality characterized by unwavering dedication.

After the Nargacuga incident in Hakum Village, Mil joined Cheval's quest to eradicate the Black Blight, adopting a radical approach. She abandoned her Aptonoth for a Brute Tigrex capable of the Kinship Skill Rock Smash. Her alignment with Cheval led to her being treated as a tool, causing her to revert to her original serious demeanor, though she became noticeably more cheerful by the end of the first season.

Shifting focus in the second season, Mil dedicated herself to aiding her friends against the Ebon Riders. She replaced her Brute Tigrex with a Seregios named Legion. Legion underwent the Rite of Channeling to gain fire abilities. Mil upgraded her equipment to a Regios Amor Set and a Cheda Blade Great Sword, replacing the Hunter's Dagger given by Hakum Village's chief before her initial departure.

Visually, Mil possesses blue eyes and purple hair, often secured with a scale-like hair clip. In the first season, she wore a pink dress, navy blue pants, and sandals. Her appearance evolved in the second season to a pink short-sleeve shirt layered over a darker pink tank top, light brown boots, and bracers, with her hair grown to shoulder length.

She shared a particularly close relationship with Lilia, feeling sadness upon learning Lilia chose not to become a Rider. As the only female Rider in Hakum Village, Mil occasionally chided Hyoro during their interactions. Her background contains no known connections beyond Hakum Village, and her development centers on shifting alliances, evolving monstie bonds, and her changing combat role.