Bujing always had an obsession for victory even if it meant sacrificing soldiers in his army. He was a general at a meeting during the early days of Fire Lord Ozai's rule. After Bujing announced his plan to use soldiers as bait, Zuko angrily denounced him for his willingness to sacrifice honorable soldiers. Because it was the Fire Lord he disrespected through his outburst rather than Bujing, Zuko is scarred by his father and banished until he can restore his honor (though Bujing himself did not seem comfortable with Ozai scarring his own son).
Bujing was later present during the meeting of Sozin's Comet, obviously uneasy around the return of Zuko, the very person who called him out years earlier. It is unknown what became of him after the end of the Hundred Year War.