While the Juggernaut has proven himself to be an unstoppable force of chaos and destruction in his base form, he is completely ignoring an upgrade that would increase his power exponentially and make him one of the most powerful beings on the planet.
Cain Marko became the Juggernaut after discovering a mystical crystal inside a hidden temple while serving in the United States armed forces during the Korean War. Little did he know, Marko found the Crimson Gem of Cyttorak which granted him incredible strength, speed, stamina, and invulnerability. By accepting these powers, Marko also accepted his role as being Cyttorak’s human juggernaut, and would be forced to bring about destruction in the demon-god’s name. Cain Marko, who already proved he didn’t have a very strong moral compass, accepted the role without question and thereby officially became the Unstoppable Juggernaut.
Related: Juggernaut Confirmed Marvel's Deadliest Power (By Being Blown to Pieces)
In New Excalibur #15 by Frank Tieri and Jim Calafiore, the Juggernaut had grown tired of being a villain and instead wished to do some good with his powers, so he joined a team of heroes to fend off a deadly threat. However, because of his change of heart, Cyttorak decided to put Marko up to a new test to see if he was still strong enough to be his vessel of chaos on Earth. During the trial, the Juggernaut faces another being who was also granted the powers of the Crimson Bands of Cyttorak, though instead of simply fighting with his fists as Marko does, this man fights with a sword. Since he is wielding this weapon, the challenger Juggernaut is seemingly able to channel Cyttorak’s unstoppable momentum through the weapon as it is strong enough to pierce Juggernaut’s armor
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