8 Video Game Heroes Who Turned Evil In The Sequel - Commenters' Edition

8. Zero - Metal Gear Series (1987-)

Despite being the only character on this list that you never actually get to play as, the effects of Major Zero's fall from grace are felt all throughout the Metal Gear series, setting in motion much of the games' main events and making him more-or-less the primary antagonist of the whole franchise.

In the 1960s, David Oh, under the codename Major Tom, was the commanding officer of FOX who guided Naked Snake (later known as Big Boss) during Operation: Snake Eater. The mission culminated in the death of his old ally, The Boss, who was revealed to be a double agent for the Soviet Union, impacting Zero to the point of turning to mercenary work.

By the end of Metal Gear Solid 4, Big Boss discovers that Zero is the mastermind behind a good chunk of the series' tragic events. He commissioned the Les Enfants Terribles project to create clones of Big Boss, and after the latter departing as a result, his new organisation, Cipher, became The Patriots, a group devoted to realising The Boss's vision of controlling an ideal world behind the scenes.

Zero, now over a hundred years old and in a vegetative state, is finally ended by Big Boss, who turns off his life support and rids the world of him for good.