With Deadpool 2 hitting theaters this past weekend, there is a lot to unpack. As expected, Ryan Reynolds and the creative team managed to stuff a ton of surprises into this thing, which explains why they were so secretive in the marketing. Lots of misdirects, but for good reason. One thing that was very noticeable is that the trailers largely ignored the villain in the sequel and those who have seen the movie know why; this movie was hiding, quite literally, a big surprise in that regard.
Warning: major spoilers ahead for Deadpool 2. If you haven't seen the movie yet and don't want to know who the big villain is, this is your last chance to turn back. There were hints ahead of time and theories that pointed to Juggernaut being in the movie and that turned out to be totally true. The massive, super strong X-Men villain was indeed a major part of Deadpool 2 and wound up being one of the most important villains in the movie. While there are several villains at play here, Juggernaut served as a nice inclusion for fans of the X-Men franchise.
Juggernaut, aka Cain Marko, previously appeared on the big screen in the much-maligned X-Men: The Last Stand, as played by Vinnie Jones. While that version of Juggernaut wasn't really a problem in that particular movie, the character feels much more at home in Deadpool 2 and, in some ways, is much more faithful to the comics. Mostly because Juggernaut is truly massive in this movie, as he is in the pages of Marvel Comics. Wade Wilson even at one point starts listing off his comic book appearances in classic fourth-wall breaking fashion, displaying that he is genuinely a huge fan.
As for how Juggernaut fits into the plot? When Deadpool and Julian Dennison's Russell, aka Firefist, are taken to the mutant prison known as the Icebox, it's revealed that a very big, bad mutant is locked far away from the rest of the prisoners. Russell then makes a deal with Juggernaut after feeling betrayed by Deadpool for them to break out of there and team up to kill his childhood tormentor, played by Eddie Marsan, who is easily the closest thing we have to a true villain in the movie.
During a prison transfer that sees Cable trying to hunt down Russell, with Deadpool and his newly recruited X-Force team trying to stop him from doing so, things get ugly and Juggernaut gets loose. This leads to the massive foe and Russell making their way to his former home. This is where the third act mostly takes place that features the remaining members of Wade's team, now partnered up with Cable, trying to stop Juggernaut and save Russell. The ensuing brawl is pretty awesome, resulting in a great fight between Colossus and Juggernaut.
Ultimately, they are able to prevail over Juggernaut and save Russell, after Deadpool sacrifices himself and, were it not for Cable's efforts, he would have been truly dead. In the movie's closing moments, we see Juggernaut moving in the fountain he was electrocuted in, so Fox could easily bring him back in a future X-Men movie, if they so choose. Even though this was one of those surprises that may have been ruined for some, the execution was so great that it should still have been satisfying either way.