He is The Juggernaut. He is possibly immortal. Definitely indestructible. And above all, unstoppable. Nothing can stop The Juggernaut. And nothing ever will. 
Appearing in "What If? Professor X Had Become the Juggernaut?"
Featured Characters:
Supporting Characters:
Antagonists:
Other Characters:
- Summers' family
- Sentinels
- Doctor Doom (Death)
- Morbius
- Tony Stark (Iron Man)
- Peter Parker (Spider-Man)
- Hulk
- Daredevil
- Wasp
- Giant-Man
- Captain America (Steve Rogers)
- Thor
- Namor
- 'Ords': Ordinary Humans
- Uatu the Watcher
- Aunt May (Mentioned)
Races and Species:
- Humans (Main story and flashback)
- Mutants (Main story and flashback)
- Atlantean-Human Hybrids (Only in flashback)
- Asgardians (Only in flashback)
- Watchers
Locations:
- Earth-905 (Reality)
Items:
Vehicles:
- Atmosphere-Cleansing Vehicles
Events:
- World War III
Synopsis for "What If? Professor X Had Become the Juggernaut?"
In this reality Professor Xavier becomes Juggernaut and is buried alive. Because of this, he never creates the X-men and the Fantastic Four instead must defeat Magneto. This causes a domino effect and causes Anti-mutant hysteria. Xavier digs his way out, now with his telepathic powers amplified to go along with super strength, takes over the country and his X-Men are used to enforce anti-human laws. The Fantastic Four, Iron Man, Spider-Man, Daredevil, Hulk and Dr. Doom are defeated and powerless to stop Xavier. Eventually, the Russians try to bomb America, starting World War III. Xavier uses his mind-leeching of scientists to come up with a way to keep the world livable. He takes over the world and announces that he won’t be a dictator, but he doesn’t want mutants messed with. Two major things change in the years that pass. One, the radiation from the war causes more mutants to be born. They make up almost half the planet now. Two, the lack of opposition doesn’t make Charles Xavier any saner.
Cain Marko is found by Magneto and on Asteroid M plotting to take down Xavier. Meanwhile, Cyclops, Jean Grey, Colossus, Quicksilver and Scarlet Witch no longer believe in this "dream" Xavier is creating (as mutants are now openly terrorizing humans) and, reluctantly, side with Magneto and Cain Marko to defeat Xavier. When Xavier finds out about the plot against him, he too comes to Asteroid M. Cyclops tries to talk some sense into Xavier, but before he can get through to him, Quicksilver uses explosives to launch Xavier into space, defeating him for now. Cain Marko leaves with Magneto. Meanwhile, Cyclops, Jean, Quicksilver and Scarlet Witch know that it’s up to them to help get the world back on its feet, no matter how hard it’ll be.
Trivia
- Although Iceman is featured on the cover, he dies in one panel in the story.
- Chris Claremont is also visually featured on the cover.