Arthur de Richemont serves as the Princess Knight of Brittany in northwestern France. She possesses long blonde hair and blue eyes, consistently attired in noble clothing. Her personality is serious and inflexible, marked by an unyielding sense of justice that frequently creates adversaries, despite her proven excellence as a soldier.

She trained at the Royal Knight Training School alongside Montmorency and Philip, forging a close bond as childhood friends. During these years, she developed secret romantic feelings for Montmorency. This affection later transformed into a rivalry with Philip for Montmorency's attention.

Her military experience includes the Battle of Agincourt, where she fell into English hands. Montmorency discovered her shattered sword on the field, leading him to believe she had died. In truth, she became a prisoner of war and pledged loyalty to the English King. Following Henry V's sudden death, she escaped captivity and returned to France, only to face exile orchestrated by La Trémoille, a powerful figure in the French court.

After her exile, she remained in Brittany, strategically navigating the complex politics of the Hundred Years' War to protect the Duchy's independence. Her eventual return to France brought renewed contact with Montmorency and placed her within the central conflict surrounding Jeanne d'Arc's emergence as a Ulysses.

While no specific supernatural abilities or combat techniques are detailed, her foundational training at the Knights Academy and battlefield experience at Agincourt establish her capability as a soldier. Her character arc centers on her unwavering commitment to justice, her fierce loyalty to Brittany, and the emotional complexities arising from her relationships with Montmorency and Philip.