Spider-Man: Far From Home Almost Included An Insane Mysterio Twist
This would have changed EVERYTHING.
The perfect part of adapting Mysterio for the big screen is how the villain essentially acts as means for the filmmakers to deceive the viewer at every step. Far From Home already featured plenty of this deception, with the villain's signature misdirection making for some spectacular sequences that blurred the line between reality and fantasy, as well as delivering two final post-credit stingers that served to turn the world of the wall-crawler (and the MCU at large), completely on its head.
The finished film was already crammed full of these extravagant twists, but the original pitch apparently featured even more attempts to surprise the viewer, with one scrapped reveal adding an extra element of deception to Jake Gyllenhaal's Quentin Beck. Speaking about early drafts, writers Chris McKenna and Erik Sommers discussed an early idea to actually make Mysterio a Skrull, knowing that they were going to be used in the MCU's future in a big way:
"There were some early, early versions of this movie where Mysterio was a Skrull. When you're doing a con artist movie, what we finally landed on-we sat down and talked about how do we keep on fooling the audience, how do we keep on having a lot of fun reveals? How many distractions can we get away with before people want to murder us? (The Mysterio Skrull reveal) was an early idea about why he was doing everything he was doing."
Apparently this idea never actually made it to a draft of the script, but it does show how open Marvel and the writers were to furthering the idea that anyone could be a Skrull in disguise, something which will no doubt become a huge part of Phase Four...