Lucretia is a pale-haired girl who is a member of the Irregulars. She possesses a Geass ability known as "The Land," which accurately maps three-dimensional terrain within a given range. The results of her perceptions are instantly submitted to her Knightmare Frame via a cockpit neuro-imaging device and collated with GPS data before being distributed to her team for tactical purposes. When her ability is active, a Geass sigil appears upon her forehead. She is typically partnered with Sancia, whose tracking Geass ability complements her own. Of the three, she is the calmest of them all and regards her team as siblings as she had lost all her relatives in the war. Source: CodeGeass Wiki