Brian's Faction were a splinter faction of the Lost Brotherhood. They appeared as the tertiary group of antagonists in TLAD.
They were formed after Billy Grey's arrest of those bikers who believed Johnny sold Billy out. Brian first attemped to have Johnny killed at the docks (fibbing that he wanted a truce with them), though this attempt failed and Brian escaped. Later Brian, informed Ray Boccino of his location at his safehouse. Ray learning of this informed Johnny of Brian's whereabouts having Johnny breach Brian's safehouse and is left with a choice to kill or spare Brian.
Kill: If Johnny choses to kill Brian the faction disolves and Johnny takes Brian's place for himself.
Spare: If Johnny choses to spare Brian, his place is still taken by Johnny. However later he calls a truce upon Johnny but is again another trap forcing Johnny to kill Brian and his men disolving the faction.