Time Lord Victorious

Time Lord Victorious was a title the Tenth Doctor briefly claimed due to his status as the terminator, final survivor, and "winner" of the Last Great Time War.

During his visit to Bowie Base One in 2059, the Tenth Doctor realised that, as the last of the Time Lords, he had control over the Laws of Time. He demonstrated this by breaking a fixed point in time to rescue Adelaide Brooke, Mia Bennett, and Yuri Kerenski. In a subsequent conversation with Adelaide, he confirmed her suggestions that he was effectively omnipotent and unstoppable; she decried the implications of his actions. (TV: The Waters of Mars)

"This is wrong, Doctor. I don't care who you are. The Time Lord Victorious is wrong."

- Adelaide Brooke

Following Adelaide's vehement rebuke and subsequent suicide, the Tenth Doctor returned to the TARDIS, pondering omens of his regeneration. (TV: The Waters of Mars)

The change to history created a Time Fracture, which the TARDIS travelled through to take the Doctor to the Dark Times. (PROSE: What the TARDIS thought of "Time Lord Victorious") There, the Doctor seized the opportunity to interfere with the Kotturuh crisis and end death by infecting the Kotturuh with a modified version of their own infection. He again declared himself the Time Lord Victorious, claiming that his word was eternal and dismissing his internal concerns that he wasn't doing the right thing. However, he was interrupted by two of his prior incarnations, the Eighth and Ninth Doctors. (PROSE: The Knight, The Fool and The Dead)

Alternate timeline
In an alternate timeline, rather than exposing himself to lethal radiation to rescue Wilfred Mott at Joshua Naismith's mansion, the Tenth Doctor judged his life to be more important and left Wilf to die. He reclaimed the "Time Lord Victorious" title and became emperor of the universe, demanding tributes from ambassadors from across the universe to help feed the starving. He was ultimately assassinated by a Raxacoricofallapatorian. The Tenth, Eleventh, and Twelfth Doctors witnessed these events after they were caught in the explosion of a Dalek continuity bomb. (COMIC: Four Doctors)

Behind the scenes

 * The alternate timeline where the Doctor becomes Emperor of the universe before being assassinated closely resembles the story of the Emperor from the novel Father Time, who was revealed in The Gallifrey Chronicles to be a future incarnation of the Eighth Doctor.
 * At VividCon 2008, a fan video debuted which juxtaposed shots from series 2, 3, and 4 episodes with the Flobots song "Handlebars", suggesting that the superficially carefree and easy-going Tenth Doctor was descending into increasingly dark and destructive actions. Writer Paul Cornell praised the video's character study as "brilliant and shocking". In homage to the video, the Tenth Doctor's subsequent turn to Time Lord Victorious in The Waters of Mars has been described by some fans and writers as going "full handlebars".