I just had this idea, of how Marvel can just have the X-Men pop up in their Universe, out of the blue, without really creating any plot holes. The story is simple: a reverse House of M storyline In sort, the reality we're living right now, is a reality created by Scarlet Witch when she was young, after a panic attack. Mutants did exist in the MCU, however the world was a cruel place for them and a war had broken out. Wanda and Pietro had a human mother and a mutant father, the famous Magneto. One event leads to another and the human mother gets killed in front of the children and Magneto. Magneto of course goes berserk and unleashes a huge rage. However, a young Wanda, having seen her mother die in front of her and the endless rage and pain of her father and the endless acts of war of the mutants and humans, snaps. She starts hitting herself, denying her own nature and screams "No more!" Pietro hugs her as an act of protection and Wanda once again screams "No more mutants!" and in a blast, the reality changes and indeed, no more mutant powered humans exist and Wanda and Pietro are the only ones left. Everybody is still alive in the current reality (Logan, Xavier, Magneto, Mystique, Cyclops, Jean etc.), but nobody remembers what they were before, but instead have new "fake memories". Wanda and Pietro do not remember either. So Marvel, just needs to make a movie where Wanda remembers and restores the memories and the powers of the mutants and suddently, mutants will appear! And then it's up to the current heroes to end the new uproar that this will create and bring balance, between humans and mutants. Dr. Strange can of course be the first one to realize that something is wrong with the current reality and that it's not what it should be. As to why Wanda needs to turn back the reality? Well because if she doesn't, some weird shit will happen that will bring the current world to an end, because "you just can't change reality into your own needs Wanda". Natural order gets lost, butterfly effect, world collapses. Classic story. Throw Loki in there, just to get all the magicians in one movie, have Onslaught as the villain and end it by revealing that the mutants have returned with cameos of the new Professor X, Magneto ready to do some damage, the new Wolverine (or not) and other mutants (except Deadpool, Deadpool movies should stay canon and he should have total knowledge of everything that's happened). Another thing they could do: Instead of having Wanda taking away the powers of mutants, Wanda could have just created a whole other Universe of mutants, also creating another version of herself and her brother. She just sent every mutant over there, banishing them fromt the current universe and thus seperating humans and mutants (she thought so). That other universe is of course the Fox universe and they could just have the two universies finally becoming one as they had to be. That keeps the entire Fox cast canon and saves all the recasts. The Watchers along with Strange find out about this other universe that shouldn't exist. Loki does somethin wrong and a hybrid from both universies is created: Onslaught. After they defeat him, the two universies become once again, whole. Plus: Maybe the reason mutants die in Logan, is because Wanda is restoring the universe, so they just return there. So, the movie can start with Logan waking up in the real MCU and trying to figure out what happened. EDIT: Can someone remove the "it" from the title?