I love that Killer7 is a game with a massive amount of back story and cut content that you will not see while playing the game, but the events in the game still play out as if some of those cut story beats still took place. There's like one or two traces in the entire game that you're being manipulated by an FBI agent named Jaco Checkbox who has access to a machine that tries to predict the future... but its predictions are very unlikely at first, and future predictions only get more accurate if the previous thing it predicted comes true. And so Jaco is running around the world orchestrating those unlikely predictions to happen so the machine's accuracy at predicting the future gets better. What!!!
There's so much stuff like that in Killer7 that's only documented in the Hand of Killer7 book that was only ever published in Japanese. It's such a mysterious game and I love that it will stay that way.