Hunter Brawn is Tristan's wealthy but mysterious father. He has caused trouble for Generation X in the past.
Hunter Brawn was laundering lots of money through the bank of which Jubilee's (Jubilation Lee) father was the president. When Mr. Lee threatened to go to the police, Mr. Brawn had both of Jubilee's parents killed.
Mr. Brawn had thus remained very wealthy. At least, until Mr. Lu, an old employee of Mr. Lee's who was in on the whole thing, confessed to the police. This led to the arrest of Mr. Brawn.
Hunter Brawn told his grandson Tristan Brawn not to worry, that his lawyers would get him out of this, to which Tristan solemnly replied, "No, they won't."
Tristan left his stunned grandfather, who sadly watched him leave. It's unknown whether the two have spoken since.