2. Edgar Ross (Red Dead Redemption)
Edgar Ross blackmails you into killing your old gang members and mentors to protect your family. In the end, all your efforts in the game was all for nothing since he eventually broke the deal and decided to wipe out everyone from the gang by eliminating John Marston.
The good thing is you can avenge Marston's death through his son Jack. Ross' death echoes his past statement that "everyone will eventually pay for what they've done."