It is happening now. The long-awaited third Deadpool movie, currently slated for Phase 5, will star Hugh Jackman and Ryan Reynolds as Wolverine and Deadpool, respectively. The pair finally reunite after 2009’s X-Men Origins: Wolverine.
How will Deadpool 3 manage to introduce Jackman’s Wolverine for “one last time” while making Reynolds a future member of the MCU? The solution could be found in an unexpected comic.
Deadpool Kills the Marvel Universe

Deadpool Kills the Marvel Universe
Wade Wilson is forcibly admitted to a mental asylum by a worried group of X-Men early in the story, which is set in a time period separate from Earth-616. The goal of Psycho-Man, a little mad scientist, is to brainwash as many bad guys as possible and build his own army of superhumans. When he tries to brainwash Deadpool, his tactic has an unexpected result. He resists Psycho Man’s attempts to control him. Instead, the violent voices inside Deadpool’s head drive him into a murderous frenzy across the Marvel Universe.
Earth’s Mightiest Heroes are targeted by the Merc With a Mouth in a determined effort to eliminate them. The Avengers, Fantastic Four, Spider-Man, Ghost Rider are all killed by him. He uses Pym Particles to create a huge version of his hammer Mjolnir to crush Thor and borrows technology from Reed Richards to kill the Watcher.
Deadpool Kills the Fox Universe

Deadpool Kills the Fox Universe
Theoretically, Deadpool Kills the Marvel Universe could translate to Deadpool Kills the X-Men Universe or something on the big screen. By doing so, Marvel Studios would be able to maintain the R-rated tone of the Deadpool films while ending Fox’s previous cinematic universe and providing fans with the Wolverine/Deadpool reunion they desire. Wade Wilson could still be sent to a mental institution by the X-Men after getting fed up with him.
Logan might be the one who pursues Wade throughout the film due to his unique skills (tracking, healing factor, adamantium claws, etc.), leading to the epic final showdown that fans have been waiting years to see on the film.