Cain Marko was a bully as a child, and his favorite target was his
younger stepbrother Charles Xavier. He changed little as he grew up, and
was incredibly jealous of Charles' success and intellect. They wound up
in the service together, where Cain's brute strength served him well. On
a mission in Southeast Asia, he stumbled upon a dilapidated temple.
Entering the temple, he stumbled upon the Ruby of Cyttorak, which held the
vast power of a extra-dimensional being. Upon touching the gem, Marko
was transformed into the Juggernaut, an unstoppable being of great strength
and durability. Over the years, he has targeted his stepbrother's X-Men,
as well as other superheroes who would stand in his way. He cares nothing
for power, his only goal is wealth and fame. Because of his his limited
intelligence, the Juggernaut has often been duped by less powerful enemies
like Spider-Man. Regardless, the Juggernaut
is feared because he is almost virtually unstoppable, even for might heroes
like the Hulk. All who oppose him do so with
caution, realizing that their fight with Juggernaut may be their last.