Even as Claire was fighting to return to Frank in Season 1 and she and Jaime were trying to stop the Jacobite rebellion in Season 2, Randall was always in the background, waiting to jump into the action and unleash his dark sadistic side on the innocent.
Randall has been the main antagonist of the series, and he did the job well.
He was the kind of truly despicable villain who tends to stick around in epic sagas, just because he’s too good at being bad for anybody to want to kill him off permanently.
While Black Jack Randall’s death is something worth celebrating for those of us who have been waiting for him to bite the dust, it does mean some big changes for the show in the rest of Season 3.