Opul Lun Sat-Yr-9 was the dictator of Earth-794, along with her lover Kaptain Briton. As a child, Sat-Yr-9 exhibited psychopathic behavior such as killing animals for amusement and later killed her parents and siblings at the age of 18, always dreaming about becoming Mastrex of the dictatorship True Briton. Her political rivals followed the same fate until she had achieved her goals. Unlike Saturnyne and Courtney, Sat-Yr-9 possesses mind-control abilities possibly derived from pheromone manipulation and hypnosis skills. A similar counterpart exists on Earth-1124, where she is visited by the Deathlok of Earth-7484 and the Killraven of Earth-691, attempting to seduce and offering herself to Killraven, although he ultimately resists her and returns to "Earth X". When Kaptain Briton flees to Earth-616, where he has an identical looking counterpart, Captain Britain, Sat-Yr-9 sends armored troops to retrieve him. They mistakenly attack Captain Britain twice, but are repelled on each occasion. Sat-Yr-9 hires the interdimensional mercenary group, the Technet, but Briton swaps places with Britain, and the Technet take the wrong man back to Earth-794. Britain later convinces the Technet of their error. When Sat-Yr-9 tries to stop them departing with Britain, the Technet slaughter her soldiers; the already psychotic Sat-Yr-9 becomes completely unhinged. She kills her subjects, leading Roma to send Captain UK on a mission to overthrow and imprison her. Later, Sat-Yr-9 seizes the opportunity to escape when an unassuming dimensional traveller from Earth-616 inadvertently enters her cell; she kills him, steals his suit and exits through the portal he came through.