Sophie Casterwill is the best friend and classmate of Lok Lambert whom she seems to like more than just a teammate. She particularly enjoys reading books, and has an excellent memory for myths and legends. As one of the last surviving nobles of the Casterwill family, she has been raised from birth to be a Seeker. Though not initially a member of the Huntik Foundation, she forged an alliance based on the need to fight evil. When talking gets nowhere, Sophie Casterwill uses powerful attack and defense magic along with Sabriel, an elegant Titan that favors speed over brawn.