Klift and Rosheen were a pair of master thieves, and part of Sheldukher's crew. By 2680, holovids had been made about their exploits, with Lithola Baxter playing Rosheen and Arrad Swanson playing Klift. The Doctor knew of worlds ruined by their crimes.
After stealing Project FXX Q84 from Checkley's World, Sheldukher and his crew went into suspended animation whilst the Project (which became the Cell) searched for Sakkrat. Before that happened, he implanted chemical dispensers in the crew's bodies.
After being awoken when they arrived at Hogsumm, Sheldukher showed his control by activating the dispensers in Klift and aged him forty years in a second. Later, he was scared to death by what he thought were ghosts in a temple on Hogsumm. (PROSE: The Highest Science)