Frederika is a dragoon, a member of the feyla race known for possessing immense magical power and physical strength. Dragoons are rare and highly sought after by warriors, as forming a contract with one grants the warrior potent abilities. Before the events of the story, Frederika was bonded to Dominica Škoda, a formidable warrior whose skills contributed to her becoming one of the Eight Heroes who defeated Emperor Arthur Gaz. After the war ended, Dominica retreated from the world and fell into a state of apathy. Frederika remained with her, desperately trying to help her master, even going so far as to take the form of Dominica’s deceased sister, Lucie, but ultimately, Dominica passed away. Following her master's death, Frederika was left alone in Dominica’s forest mansion for years with no purpose, merely imitating her lost mistress to stave off boredom.

The arrival of Chaika Trabant and the saboteur siblings Toru and Akari Acura at the Škoda manor gave Frederika a new direction. Initially, she was curious about the group’s motivations, but after being thoroughly outmaneuvered and defeated by Toru and Akari, she willingly surrendered the remains of Emperor Gaz that she was guarding and decided to join their journey. Frederika is characterized by a love for combat and a desire for a good fight, often rushing into battle with enthusiasm. She has a mischievous and playful personality, frequently teasing the other characters. She often takes the form of a small cat, using this disguise to observe situations or interact with others, and has also been known to assume the appearance of her former master, Dominica, and Dominica’s sister, Lucie. Her primary motivation for joining Chaika’s group is to find a new purpose in life after the death of her master, seeing the journey as an opportunity for excitement and a chance for a rematch with Toru, whom she acknowledges as a skilled fighter.

In the story, Frederika serves as a powerful ally and a source of immense magical power for the group. Her most significant role develops when she forms a pact with Toru Acura, allowing him to become a Dragoon Cavalier. This bond grants Toru enhanced abilities necessary to confront powerful enemies, such as the resurrected Emperor Gaz and his followers. Her key relationship is with Toru, whom she sees as a worthy opponent and eventually a partner through their dragoon contract. She also shares a close camaraderie with Chaika and Akari, functioning as a guardian and combatant for their cause. Frederika undergoes notable development from a listless, purposeless being trapped by her past into an active participant with a new reason to live, fully committing to the group’s mission and forming a new bond with Toru. As a dragoon, her notable abilities include transforming into her true, powerful dragon-like form for combat, shape-shifting into various human forms, and granting her contracted partner, the Dragoon Cavalier, access to formidable dragoon magic and strength.