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 decided he had gone too far and returned to the TARDIS, pondering the omens of his regeneration. (TV: The Waters of Mars)

Alternate timeline
In an alternate timeline witnessed by the Tenth, Eleventh, and Twelfth Doctors after they were caught in the explosion of a Dalek continuity bomb, rather than rescuing Wilfred Mott and regenerating at Joshua Naismith's mansion, the Tenth Doctor judged his life to be more important than Wilf's and let him 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. (COMIC: Four Doctors)