Darth Vua was a Yuuzhan Vong Slayer who fought during the Yuuzhan Vong War and was later recruited by the One Sith as a Sith apprentice.
Darth Vua was a male Yuuzhan Vong Slayer who was active during the concluding stages of the Yuuzhan Vong War. Like all Slayers, Vua was bred from Force-sensitive Human slaves grown from tissue samples taken from Jedi that had been augmented and transformed by Yuuzhan Vong shapers to serve Supreme Overlord Shimrra Jamaane as elite warriors. At some stage, Vua became bethrothed to another Yuuzhan Vong. Shortly prior to the Battle of Yuuzhan'tar at the conclusion of the war, Vua was dispatched on the orders of Shimrra to fly a Slayer ship poisoned with the pathogen Alpha Red onto the living planet Zonama Sekot in an attempt to kill the sentient world. However, Zonama Sekot used its gravitic power to fling the starfighter away and Vua's mission was unsuccessful. Soon afterward, the Yuuzhan Vong surrendered during a final battle over Yuuzhan'tar and the surviving Vong, including Vua's bethrothed, were sent to live on Zonama Sekot.
Following the battle, Vua came to be regarded by the galactic population as analogous to one of the Yuuzhan Vong's enemy, the Jedi Master Luke Skywalker, as a lone pilot who had taken on an entire weaponized world; Skywalker having destroyed the Death Star battlestation during the Battle of Yavin of the Galactic Civil War. In the aftermath of the Yuuzhan Vong War, Vua was captured by the One Sith, a resurgent Sith Order active on the planet Korriban and was forced to become a Sith apprentice, adopting the Sith name "Darth Vua". The former-Slayer later created a personal holocron in which he recorded his thoughts about his role in the defeat of the Yuuzhan Vong.
Darth Vua felt responsibility for the defeat of the Yuuzhan Vong, believing that it was because of his failure to destroy Zonama Sekot that his people were forced to surrender and settle on the living world. He also rejected the comparisons of him with Luke Skywalker because Skywalker had been victorious when he attacked the Death Star, whereas Vua had been defeated when he flew against Zonama Sekot.
Vua also believed that One Sith had tried to imprint Jeedai thoughts inside his mind in an attempt to break him, but he maintained his resolve and refused to surrender to their way of thinking.
Darth Vua was first mentioned in the StarWars.com article Star Wars: The Essential Guide to Warfare: Author's Cut, Part 12: Tales of the New Republic, an article in series by Jason Fry and Paul R. Urquhart that published content written for the reference book The Essential Guide to Warfare that didn't make the final cut. Vua was to be referenced within a brief extract from his personal holocron written from an in-universe perspective and the subsequent publication of the content in Author's Cut brought it into Legends continuity. The extract references the events of the novel The New Jedi Order: The Unifying Force which depicts the attempt by a Slayer ship to poison Zonama Sekot with Alpha Red, by establishing Vua as the vessel's pilot. Urquart intended for this piece to act as a conclusion to the Yuuzhan Vong section of the Essential Guide.