Re: This Franchise Needs a Reboot Bad
If they were to do Juggernaut properly, he could have been a soldier in Vietnam with Wolverine and could have been mutated by some radioactive material he found in a cave, the equivalent of that Cyttorak gem.
But it made sense to just make him a mutant when they put him in X3. Unfortunately, they didn't make very good use of him - just one action scene, and that silly line taken from a YouTube video that no one thought was funny. It was hardly worth including the character for that. (Same with Multiple Man, Arclight and Angel).