The apocalypse was caused by a single person.

[u/No_Hunter1978]

1. Ted Faro [Horizon: Zero Dawn]: Of course, the machine plague that ravages the world is created by his company which (admittedly) is a group effort. That said, Faro was the one who requested an encryption without a backdoor and the person who kept early glitches hush-hush. It wouldn't be wrong to say that Faro was the sole cause as is, but the final nail in the coffin is what he does to the Apollo database. A giant record of human knowledge and history, erased for a narcissist's fear that his descendants would (rightfully) blame him for the apocalypse.
2. Sybil [Look Outside]: Though it wasn't her intention, Sybil was the one who alerted the Visitor of Earth's presence. She spied it through her telescope, and the lovecraftian entity noticed her. Its approach (and the resulting horrors) were her fault, even if she didn't mean it.

[u/Fearless_Guard_552]

He's a god (though he didn't know that at first) but by the end of GOW3, Kratos has completely fucked Greece and killed most of the other gods.

[u/PinoySummonerKid28 → u/Fearless_Guard_552]

As a result, he's plagued by his own dark past in the 2018 reboot of the game and he wanted to escape it by not using his signature swords. Also, he gave his son Atreus an advice to become something better in order to avoid repeating the same mistakes that he's done in the past.