X-Men Dark Phoenix: 10 Biggest Unanswered Questions We Still Have

2. So, What About Mister Sinister?

Apocalypse's post-credits scene teased the presence of Nathaniel Essex aka Mister Sinister, seeming to suggest that the iconic comic baddie would have a major role in the next mainline X-Men movie.

But Dark Phoenix came and went without a peep from the antagonist - despite rumours last year that Jessica Chastain was playing a gender-swapped "Miss Sinister" - so what happened to those plans?

The Likely Answer

Despite the obviously intriguing potential of adapting Sinister to the big screen, the character's introduction hit several speed bumps in recent years.

First and foremost, he was originally going to have a role in Logan, before James Mangold decided that it would interfere with the film's "grounded" tone (but mutant clones didn't, apparently).

Word then leaked that a post-credits scene for The New Mutants was shot featuring the character, with Jon Hamm cast to play Essex, but this was ultimately ditched in favour of a new scene featuring Antonio Banderas as a currently unspecified villain.

Sinister's absence reeks more of poor planning than anything - he seemed like a pretty obvious go-to after Apocalypse, but Kinberg and co. clearly weren't sure of exactly how to integrate him into the franchise.