Champion

Champion was a title for the defender of a place, person, or concept. (TV: The Christmas Invasion, PROSE: Love and War, et al.)

The Eternals occasionally bestowed the title upon Time Lords who made deals with them. The title came with certain abilities and privileges in exchange for a payment. (PROSE: Human Nature) For instance, to become Time's Champion, the Seventh Doctor sacrificed his prior incarnation to the Eternal Time. (PROSE: Love and War) Death also had her own champion, (PROSE: No Future) and on various occasions, the Eighth Doctor was described as Life's Champion. (PROSE: Vampire Science, The Dying Days)

According to the sanctified rules of combat, the Tenth Doctor stood as champion of the planet Earth against Fadros Pallujikaa of the Sycorax on 25 December 2006. After defeating the Sycorax in a sword duel, he ordered them to leave the Earth and never return. (TV: The Christmas Invasion)