Twenty years later Gasback has hunted down two of the three men who betrayed him and has taken his revenge by stealing their wealth and destroying their businesses, property and possessions. Gasback travels to Macca City to confront Cain, the final henchman and he succeeds in stealing the city's power Plant. He is pursued by a revenge-seeking bounty hunter named Amelia Ann McFly, Vash, and Nicholas D. Wolfwood, but Vash is injured in a shootout and presumed dead leaving only Amelia and Wolfwood to attempt to rescue the Plant and bring the thief down. Vash survives his gunshot wound and arrives on the scene in time to save Amelia from one of Gasback's henchmen and the thief challenges Vash to a duel which the Humanoid Typhoon wins.
It is then revealed that Gasback is, in fact, Amelia's father who had left her mother many years ago to pursue his life of crime. Gasback left her and his unborn daughter well provisioned, but rival thieves stole much of what they owned except for a special glove that Gasback made for Amelia's mother to protect her. Amelia uses this glove to counter an energy-based weapon that Gasback uses in an attempt to defeat Vash. Amelia decides to follow Vash's example and does not kill Gasback, but allows him to be taken into custody. He is last seen in chains contemplating the actions of Vash and Amelia.
Gasback's primary weapon is a mechanical gauntlet that he wears on his right arm which contains a rotating, triple-barreled machine gun and rocket launcher. The heavy gauntlet is flight-assisted to relieve some of the weight using small jet engines. It also conceals an energy weapon that emits arcing bolts of electricity and can act as an EMP. This energy weapon is able to be countered by a special glove that Gasback designed and gave to his wife, presumably to protect her from the weapon while traveling with the thief.