Kallen is a highly skilled Knightmare Frame pilot, rivaling the abilities of even the Knights of the Round. She is acknowledged as the best pilot of the Black Knights by enemies and allies alike. Her codename, "Q-1," is the Queen's starting spot in descriptive chess notation. In Lelouch's assessment of the core members of the Black Knights, her "Combat Ability" score is 100 out of 100, matching that of Kyoshiro Tohdoh; she also has the highest possible "Loyalty" score of 100.