Engin

Coordinator Engin worked in the the Archives on Gallifrey. He sent the Fourth Doctor into the Matrix to do battle with Goth. After was defeated, Engin was put on the Committee of Inquiry. (TV: The Deadly Assassin)

After Niroc became President, another Time Lord was appointed as Keeper of the Matrix, prompting the Sixth and Eighth Doctors to select Engin when arranging an inquiry in the Sixth Doctor's trial, reasoning that he might be old but he possessed a clearer knowledge of the Matrix than any other. (PROSE: The Eight Doctors)

Engin was still Keeper of the Matrix during the Last Great Time War. He spoke with Priyan about the Doctor's actions and how the War would end. (COMIC: Sky Jacks)

Behind the scenes

 * Engin appears (albeit regenerated) in NOTVALID: Incoming Transmission.