Thorken Menanius

 was a Taklarian scientist. He developed a brainwashing device. It was used on Barbara Wright so she would unwittingly help the Taklarian invasion of Arkhaven to gain control of the ship being built to escape Sarath's destruction. However, the ship was a sham and Brantus Draad blew it up once the Taklarians were onboard. (PROSE: City at World's End)