Hilling is the second queen of the Bosse Kingdom, having married King Bosse after the death of his first wife, Sheena. Before her life in the royal court, Hilling traveled as a monastic, a period during which she likely developed her powerful restorative magic and formed lasting bonds, such as with her former bodyguard, Ann. She is the biological mother of Prince Daida and the stepmother to the first prince, Bojji.

On the surface, Hilling often presents herself with a brusque, distant, and demanding demeanor, a behavior she considers befitting her royal rank. However, this exterior masks a deeply caring, if socially awkward, individual. Her sharp tongue and domineering nature frequently clash with her genuine affection for those around her, leading others to initially misunderstand her intentions. This is particularly evident in her relationships with her sons, where her love often manifests as fierce protectiveness and high expectations, which can be overwhelming for them.

Hilling’s primary motivation is the safety and well-being of her family. This drive is the core of her character, pushing her to take extreme measures to protect her children. She is fiercely determined and self-assured, willing to defy councils, lead military assaults, and even confront the possessed body of her husband to rescue her son Daida. Her role in the story evolves from that of a seeming antagonist who supports Daida over Bojji for the throne to a central figure of maternal strength. She is a key player in the political struggles of the kingdom, a master healer on the battlefield, and the emotional anchor fighting to reclaim her son from the consciousness of King Bosse.

Her most significant relationships are with her two sons. While she initially conspired to make Daida king due to her fears for Bojji's safety, she shares a deep and complicated love for her stepson. She worked hard to earn his trust when he was young, learning sign language and baking him cakes, but that affection eventually curdled into a severe overprotectiveness that underestimated his abilities. She has a similar protective, yet demanding, love for Daida, pushing him to become strong to defend his brother, a pressure that fueled his initial resentment of Bojji. Her relationship with her bodyguard, Dorshe, is one of her closest; he is one of the few who understands her true nature and remains a loyal ally. Her bond with King Bosse is shown through brief, happy flashbacks, but his eventual possession of their son turns him into the primary target of her anguish and fury.

Throughout the series, Hilling undergoes significant development. She begins as an overbearing figure who underestimates Bojji, but she gradually learns to relax her grip and accept his capabilities, ultimately becoming one of his staunchest supporters and advisors. A pivotal moment is realizing that her overprotectiveness drove a wedge between them, prompting her to change her behavior. Her devastation when Bosse takes over Daida’s body shifts her entire purpose toward a desperate, single-minded quest to get her son back, showcasing the depth of her maternal resolve.

Hilling’s most notable ability is her powerful restorative magic. She can heal wounds, cure poisons, and even revive the recently deceased, though this power leaves her physically exhausted. In the special episode "The Treasure Chest of Courage," she demonstrates a spell called the "Death Promise," a bluff she uses to intimidate bandits into reforming by claiming they will die if they commit violence again. This moment highlights not only her magical prowess but also her cunning and her belief in rehabilitation over retribution. Her healing abilities are described as being fueled by a strong desire to heal someone, a philosophy she later imparts to a young Daida, who successfully uses the magic to heal an injured Bojji.