Dengar Vassel is a human replica droid, former Bounty Hunter and one-time renowned Corellian pilot of both swoops and starfighters.
He was once the greatest swoop-racer on Corellia. After a major swoop-bike accident left him with major brain damage, he had sections of his mind removed and replaced them with mechanical alternatives. Aiding in accuracy and reactions, he enlisted in the Imperial Academy as a sniper before becoming a commando. Eventually, he became a pilot.
But Dengar was losing faith in the Empire, and slowly began to see that - whilst he didn't care about the many suffering people - he cared about profit. He left the Empire, buying a range of weaponry and becoming a Bounty Hunter, determined to become rich in whatever way he could. However, the Empire wouldn't let him leave the Academy. Dengar had to escape, and soon after found a large bounty on his head.
Not much was revealed about the time after this, but it was known that he worked with other bounty hunters such as Boba Fett. Eventually, he joined The Dantooine Lance, in an attempt to attack the Imperials that had betrayed him. Claiming twenty-three kills at Gravlex Med, beating his friend Dari by one, he upgraded his ships to XJ3-Wings, and led the starfighter corps for the ShieldMark Alliance.
As the Shieldmark became the New Galactic Republic, Dengar gained even greater fame and fortune as a starfighter pilot. The bounty had been dropped from him, and he was finally content.
But that wasn't all. The Galactic Republic collapsed and Dengar was forced to work as a bounty hunter again, moving to join the Mandalorians under Kyp Durron. Kyp vanished mysteriously one day, and put a bounty out on his own head a while later. Knowing that he was in trouble, Dengar chased after him, eventually locating the remains of the Shadow Academy and following the path of destruction to a fight between several people - Kyp, Lucy Durron, Admiral Daala, Commodiorus and Tigernmas - on Mustafar.
Engaging himself with Commodiorus, the stronger Bounty Hunter found himself easily defeating Dengar, and eventually knocked him into the lava. Dengar was retrieved by one of his workers, but his body was so mangled that his remains were forced to be converted into a massive cyborg machine, that named itself the Dreadnought.
Dengar, as the Dreadnought, attempted to hunt down Commodiorus, but was halted by Chaplain Meliadus, who immobilised his motors and left him for dead. A long while later his mind was transferred into a human replica droid as close to his original appearance as possible but stronger. Since the factory was destroyed, however, Dengar hasn't been seen.