Seventh Doctor (Death Comes to Time)

In one reality, the Seventh Doctor travelled with Ace and Antimony at a point in time when he was one of the last of the Time Lords alongside the surviving members of the Fraction.

Biography
The Doctor saw the Canisians destroyed in a war started by Tannis, but he saved a few survivors of the species in his TARDIS. He then investigated the deaths of his fellow Time Lords Valentine and Antenor. During these events he met the Minister of Chance. The Doctor later led a further investigation into the Blue's Bar massacre with the assistance of Speedwell, so together they discovered Nessican was responsible for the deaths. Due to the events the Doctor poisoned Nussican with his blood after consuming garlic.

Later on, he tried to defeat Tannis' plot of invasion. Upon doing so he rescued Bedlar's child, eventually meeting face to face with Tannis when returning the child. A frustrated Tannis shot the Doctor's beloved companion Antinomy to death. The Doctor was now in despair, so he travelled back to companion Ace where they noticed the death of Nuscan.

The Doctor caught up with the Minister of Chance and convinced him to stop his madness. The Minister threatened to kill the Doctor but eventually backed down, accepting the Doctor's judgment as the Doctor, vested with the authority of the Fraction, "revoked" his old friend's TARDIS and left him to consider his mistakes. He returned to Earth one last time to kill Tannis and stop his attempted invasion of Earth, assisted by The Brigadier. He confronted Tannis on Salisbury Plain, preventing him from killing Ace. Tannis, who had expected the Doctor to let Tannis kill him rather than break the Laws of Time, was stunned when the Doctor revealed that the time had finally come for him to break his vows and call upon his full powers as a Time Lord, precisely to stop Tannis from doing the same and taking over the universe with no one left to stop him. The Doctor "disrupted the course of time", seemingly destroying both Tannis and himself. Only his umbrella was left behind, to be found by Ace. However, just before vanishing, the Doctor had calmly noted that he had "been dead before".

Ace, who had been trained in Time Lord way by Casmus, met with the Kingmaker who formally inducted her as the first new Time Lord of this new age, in line with the Doctor's pre-mortem statement that his own kind had no place in the universe anymore, and it was up to humans to forge their own path from now on. However, the Kingmaker also cast doubt over whether the Doctor was truly, fully dead in the way Ace had assumed, noting that an idea couldn't be killed, and the Time Lords of old were more ideas than people. (WC: Death Comes to Time)

When exposed to anti-time, the Eighth Doctor of the positive-time universe saw a reality where the Time Lords had "terrible mind powers", (AUDIO: Zagreus) matching the mysterious powers which, in this account, Time Lords were said to inherently possess as "Gods of the Fourth" despite being sworn never to use them. (WC: Death Comes to Time) According to one account, in the post-War universe of the Eighth Doctor, Tannis was a threat Gallifrey had yet to face, seemingly establishing the events involving the Seventh Doctor as a different timeline from his, (PROSE: The Gallifrey Chronicles) though another account dealing with this same version of the Eighth Doctor acknowledged the Canisian invasion. (PROSE: Trading Futures)