The Unreliable Narrator
It turns out, everything you thought you knew was a lie. The protagonist was actually a cyborg, and the whole story was a simulation created by a mischievous AI. The "twist" was that the "hero" was never really the hero at all, but rather a pawn in a much larger, more sinister game.
Learn the truth about the real hero of the story, and the true mastermind behind it all.