Castellan (Engines of War)

The Castellan was a Time Lord on the High Council during the Last Great Time War. He aided Karlax in initiating a mind probe on Cinder. However he did not enjoy this work, and hid Cinder behind Rassilon's portrait so she could recover. When the War Doctor tried to escape Gallifrey with Cinder, he found the codes had been changed meaning his TARDIS was trapped. The Castellan tried to persuade him to surrender, but the Doctor told him he wouldn't be able to have the deaths of the people of the Tantalus Spiral on his conscience. The Castellan transmitted the codes, enabling the Doctor's TARDIS to dematerialise. Karlax suspected the Castellan had helped the Doctor escape, and told Rassilon he would investigate the matter. It is unknown whether Karlax was able to do so, as shortly after Karlax left with the CIA to kill the Doctor. (PROSE: Engines of War)