- You may be looking for the Time Lord of whom this Doctor was the sentient mirror image..
A Mirror Image of the Eighth Doctor was created in Mirror Edinburgh when the Eighth Doctor gazed into one of the Silversmith's mirrors. Appearing grim and depressed, the Mirror Doctor informed the real Doctor of the Silversmith's Mirrors' nature as transdimensional portals to an unstable pocket of unreality just before the Doctor was confronted and captured by the Mirror Silversmith. Like the other Mirror Folk, the Mirror Doctor ceased to exist when the Doctor, alongside Josie Day, freed the human prisoners who had been unwillingly feeding psychic energy into the Spherion crystals to sustain Mirror Edinburgh's existence. (COMIC: The Silvering)