X-Men: The Last Stand seemed like an obvious movie to make. After establishing characters and plots for two movies, adapting one of the most popular X-Men storylines seemed like a surefire way to create more money for the franchise. It did do that, but took some severe criticism for its awkward pacing, use of characters, and deviation from the original storyline.
Most of the fault was blamed on the change in director, seeing as how Bryan Singer (the director of the first two films), wasn't here for this one. Well, as it turns out, Singer would've made a lot of changes from Brett Ratner's version. They all sound absolutely amazing to me (at least on paper). So here's what he would've done:
It Would Only Be About the Dark Phoenix Saga
The original film was sort of an amalgamation of any stories that involved Jean Grey and some ideas from the writers. This made everything a little bit confusing for comic-book fans. Well, one thing Singer would do differently would be just to focus on one storyline: The Dark Phoenix Saga. That sounds like something that would've made everything a bit more streamlined, making it an easier plot to understand for everyone. Jean Grey would return with a "new, more destructive personality called the Phoenix", much like in the actual movie. But there's a huge twist:
She Would Be Manipulated into Joining The Hellfire Club
This is where Singer's version gets interesting: after returning as the Phoenix, The Hellfire Club (seen in X-Men: First Class) would find her and manipulate her into joining them. How? Through a certain telepath named Emma Frost. In this version, Emma Frost would be the leader of the club. Oh! And Sigourney Weaver would be playing her.
A Three-Way War Would Ensue
Ratner's version of the movie saw the X-Men fighting Magneto's Brotherhood of Mutants, while both fought the humans because of the cure, though the only action was between the two mutant groups. But what we were supposed to see would've been a real spectacle: The Hellfire Club vs the X-Men vs The Brotherhood of Mutants. There'd be an evil group against a good group against a not-as-good-but-not-as-evil group. The Hellfire Club would want her to take over the world, the X-Men would want to save their friends, and Magneto and his followers would want her for their own plans. Besides the sheer scale of that war, imagine the visuals! Just about any mutant power you can think of would be on display. That's all fun and good, but who would get her? The answer may surprise you:
Jean Kills Herself to Save Everybody
That headline is amazing as it is, but the comparison by the X2: X-Men United screenwriter makes it sound even better. Basically, in the end, a torn Jean kills herself, but not really. While her body is deceased, her sprit lives on, and "transcends into a divine being", which he compared to the star child from 2001: A Space Odyssey. This way, the cosmic version of the Phoenix Force is created and could be brought back for future movies.
So those would be the major plot points, but what about some extra information about the movie? Well . . .
A Distraught Cyclops Would've Built the Danger Room
The Danger Room was introduced in the third X-Men movie, but its origins are unknown. If Bryan Singer had his way, however, it would've been created by Cyclops towards the end of the movie, shocked by the power that the Phoenix had. He felt that the X-Men needed to be stronger and more ready for the next battle, so he would create the Danger Room at the end of the movie.
Phoenix Jean Would Go Around the World Saving Mutants
Thoughout the course of the movie, multiple characters would be fighting each other, but what would our main character be doing the whole time? Well, she would be saving trapped mutants around the world! This could've opened up the door to dozens of cameos. Maybe one of them could've been Gambit! Speaking of Gambit . . .
Keanu Reeves Was the Choice For Gambit
Taylor Kitsch? More like Taylor Kitschy. Channing Tatum? It should be Channing Tat-um...no. Keanu Reeves? I think it'd be more appropriate to say "Kean-u-please give me this casting." Sad Keanu no more, it's all about sad Gambit! It would've been amazing.