Vivant held the positions of first officer, and later commander, aboard the Imperial Star Destroyer known as the Steadfast. He initially served as first officer under the command of Grand Admiral Afsheen Makati while they investigated a Rebel base located on Thila. During this investigation, the Steadfast received assistance from Supreme Prophet of the Dark Side Kadann, who overheard Vivant making fun of his elaborate clothing. Kadann then reprimanded Makati for the insubordination displayed by his first officer, causing the Grand Admiral embarrassment in front of the assembled crew.
Following Makati's death, Vivant eventually rose to the rank of commander of the Steadfast. In 11 ABY, the ship became part of Carnor Jax's battle fleet. Vivant commanded the Steadfast to provide support to the Emperor's Revenge as it bombarded New Republic forces stationed on Phaeda. Ultimately, Vivant was compelled to surrender when Rogue Squadron arrived, accompanied by the even more formidable Lusankya.
An earlier iteration of Who's Who: Imperial Grand Admirals, which was originally intended for publication in Star Wars Gamer, identified Vivant as the first officer of the Steadfast during the time it was under the command of Grand Admiral Afsheen Makati. However, due to the cancellation of Gamer, the article was rewritten for inclusion in Star Wars Insider. While the final version omitted Vivant's name, it still alluded to the events and the ship's first officer that had been detailed in the original draft, although with less specific information.