9. Mordo Hunts Down Sorcerers - Doctor Strange
The first Doctor Strange film ended with a credits tease so blatant that it seemed absolutely certain it'd be directly followed up in the sequel, but alas it never happened.
Doctor Strange's post-credits scene saw Baron Mordo (Chiwetel Ejiofor) attack Jonathan Pangborn (Benjamin Bratt) and steal the mystical energy he used to cure his paralysis, before telling him that Earth has "too many sorcerers."
The implication was clear, that Mordo was going to start hunting down sorcerers on Earth, as would inevitably bring him back into conflict with Doctor Strange (Benedict Cumberbatch) - a showdown fans quite understandably expected to see in Doctor Strange in the Multiverse of Madness.
But in fact, the original version of Mordo from Earth-616 is nowhere to be seen in the sequel, with the Earth-838 variant instead making an appearance.
Beyond Strange mentioning in passing that the 616 Mordo had made a few attempts on his life, he was basically a non-entity in the movie, much to many fans' disappointment.
It later emerged, however, that 616 Mordo was originally supposed to appear in the film's opening scene, where he would attack Wanda (Elizabeth Olsen) and she would respond by decapitating him and later presenting his severed head to Strange.
According to the filmmakers, it was cut because it slowed the opening sequence down and "didn't have a place in the movie," leaving 616 Mordo in an awkward sort-of limbo where his true fate remains unknown.
Hopefully if Doctor Strange 3 does indeed happen, we'll at least get a Mordo cameo to finally tie things off.