It's never a nice thing to witness a friend or close ally turn towards a darker route in life.
Whether through literature or the silver screen, we've seen all too many companions fall to their own greed or self-interest, yet video games take this concept and add an interesting twist.
As they are experiences the player has a direct hand in, they can make that heel turn even more of a gut punch by having prior protagonists turn into major villains in the sequels.
Here the sting is even worse when we don't just know of the events prior to their fall from grace, but actively had a hand in helping them get to where they were!
Thankfully not all of the examples on this list remained within the shadows of evil and sought to redeem themselves, but for a time these big bads were prior nice lads!
8. Jin Kazama - Tekken 6
In arguably one of the best fighting games ever created, the almighty Tekken 3 introduced fans of the series to a slew of new fighters, mostly representing the next generation of people willing to punch that pesky old spine right out of the back of you.
However, of all of these second and third generation fighters, one stood at the top of the pile as a child literally born to brawl, Jin Kazama, the love child of Kazuya and Jin.
His style and awesome moveset made him an instant fan favourite, however, it was soon clear that this prodigy wasn't going to end up being the hero of this narrative.
After being used by his grandfather Heihachi, developing Devil Powers and finding out his trashbag father was still alive, Jin became disillusioned with the Mishima bloodline, leading to him vowing to destroy them all.
Yet, the rotten apple didn't fall far from the tree and soon enough Jin had disposed of his rivals and taken over his family company Mishima Zaibatsu, and set about using this vast wealth and power to put a stranglehold on the world.
Luckily he does seem that the ending of Tekken 7 is setting him up to become a hero once more, but man did he have a dark time during what one could term his "gap year".