Braxton

Captain Braxton was a male Human Starfleet officer serving in the 29th century. During his career he was known to command the USS Aeon (Epoch class) and the larger  USS Relativity (NCV-474439-G), using both to travel back in time and undo changes in the timeline. In the 2370s, he has encountered the crews of at least two Starfleet ships of that time: that of the USS Excalibur (NCC-26517) at least once and that of the USS Voyager at least twice. 

Encounters
Braxton was first encountered by the crew of the USS Voyager in 2373 when the Aeon appeared in the Delta Quadrant and attempted to destroy Voyager after Braxton informed Captain Kathryn Janeway and her crew that there was evidence that the starship was responsible for the Sol system's destruction in the 29th century. Voyager was able to disrupt the Aeon's systems, and was pulled into a temporal rift and crash-landed on Earth in 1967. Braxton was able to escape, but the Aeon fell into the hands of Henry Starling and became irretrievable.

Over the next thirty years, Braxton was forced to live as a tramp and vagrant in 20th century Los Angeles, becoming paranoid and aggressive, as he watched Starling use technology from the Aeon to spark a technological revolution and become extremely wealthy in the process. Following Voyager's arrival in 1996, Braxton was able to make contact with Janeway and together they managed to stop Starling in his attempt to take the Aeon to the 29th century, which originally caused the Sol system's destruction.

Following the resolution of the temporal paradox, a Captain Braxton who had not experienced these events returned Voyager to the Delta Quadrant in 2373. 

Braxton was then taken back in time to 2293, to Khitomer, where he stopped Captain James T. Kirk from saving Federation President Ra-ghoratreii from his assassins. He also removed Kirk to prevent anyone from tampering with the new timeline. Braxton then had Captain Jean-Luc Picard brought onboard the UTS and informed him of an unknown event on time's horizon that would destroy the Milky Way Galaxy.

The following year, the crew of the USS Excalibur (NCC-26517) encountered Braxton, now commanding the USS Relativity (NCV-474439-G), when Captain Mackenzie Calhoun had the Excalibur slingshot back in time in order to help the people of Haresh fight off a Redeemer attack and save their planet. Braxton transported aboard the Excalibur and attempted to convince Commander Elizabeth Shelby to go against her captain and stop their action, but she decided to support Calhoun. As the Redeemer ship approached, Braxton initially ordered that the Excalibur be disabled so that they couldn't interfere, but later ordered her destruction after Calhoun ordered a collision course with the Relativity. Just as they were about to fire, a massive Enevian starship from 1500 years in the future arrived and ordered that the Relativity and the Redeemer ship depart as both Haresh and the Excalibur were under their protection. Overpowered and outgunned, Braxton and the Relativity returned to the 29th century. 

Voyager's next encounter with Braxton came in late 2375, when the ship was destroyed by a temporal disruptor. Braxton had Seven of Nine transported to the Relativity prior to Voyager's destruction, and enlisted her help in traveling to Voyager at various points in its history to determine who the temporal criminal was who planted the disruptor. It was eventually determined that an older version of Braxton himself was the criminal, having succumbed to temporal psychosis at some point in the future. The original Braxton plus two other versions recovered by the Relativity underwent temporal integration. Lieutenant Juel Ducane assured Captain Kathryn Janeway and Seven of Nine that Braxton would stand trial for the crimes that he was going to commit.