10 Iconic Comic Book Storylines That Are Currently Impossible

10. Secret Invasion (Marvel)

The 2008 Secret Invasion arc involved a subversive, long-term invasion of Earth by the alien race known as the Skrulls. Capable of shapeshifting, the Skrulls had secretly replaced many of Marvel's major superheroes with Skrull impostors over a long period of years, prior to the main invasion. It would be impossible to do in the current comic book movie climate, as the Skrulls aren't owned by Marvel Studios and their replacements in the Marvel Cinematic Universe - the Chitauri - have shown no signs of having any shapeshifting powers, so suddenly giving them to them would be silly. Plus, there has already been a massive infiltration storyline with HYDRA and S.H.I.E.L.D. so it would be far too repetitive. You might think it's possible in the Fox universe, but the whole alien thing wouldn't fit in the X-Men world and the Fantastic Four don't exist in that universe yet so, while it could be possible in the future, it certainly isn't at the moment.