Jostero existed as a male privateer who served as the captain for the Silestro Privateers throughout the Galactic Civil War. The asteroid known as the Rayless Lantern, situated within the Pirate's Shadow belt, served as his base of operations.
Captain Jostero piloting his personal Kihraxz assault starfighter
During the conflict, he challenged Tala, who was a pilot, to a swoop competition. The privateers intended to eliminate Tala and her companions, seizing their possessions regardless of who won. Tala emerged victorious; however, before the privateers could launch their assault on the trio, a speeder belonging to the Corellian Security Force appeared, causing everyone involved to disperse.
Later on, Jostero attempted to infiltrate a starship utilized by adventurers working for Gustip, who was the majordomo of the wealthy businessman and crime lord, Baron Benton Kaldo. He deployed his ship, the Bloodblade, a Firespray-31-class vessel, accompanied by a pair of CloakShape fighters.
Jostero also possessed and flew a Kihraxz assault fighter that was customized with a unique paint scheme.