"No one tricks the Juggernaut! There won´t be enough of you left to bury."
—Juggernaut to Thanos in Marvel Super Heroes.
The Juggernaut is a character that appears in X-Men: Children of the Atom as a non-playable penultimate boss, later becoming playable in Marvel Super Heroes, X-Men vs. Street Fighter and Marvel vs. Capcom 2, and also appears in the first Marvel vs. Capcom as a summonable assist character
Cain Marko was the son of Dr. Kurt Marko, who was an atomic researcher. Cain's parents separated and Cain was eventually sent to a boarding school. Kurt Marko's colleague, Dr. Brian Xavier, another atomic researcher, died in an accident, and Kurt Marko eventually married Xavier's widow Sharon for her great wealth. On marrying Sharon, Kurt Marko moved into her large Westchester County mansion, where he lived with her and her young son Charles. Cain, who had become a cruel and spiteful boy, came to live at the mansion as well. He evantually went to serve in the military with Charles. When they went to Korean War, Cain found a temple containing a large power, and took it. However, he was buried alive, with Charles thinking he was dead. Marko, eventually dug himself free with his newfound power and made his way to America to use his power to kill Xavier. He was defeated by Xavier and his original team of X-Men with the help of the Human Torch. Over the years the Juggernaut has clashed with Xavier and both the original and new teams of X-Men repeatedly. He has also formed a successful criminal partnership with his old friend Black Tom Cassidy.
When Cain Marko finds the Gem of the mystical entity Cyttorak, he is empowered with magical energies and transformed into an immortal avatar. As the Juggernaut, Marko possesses superhuman strength; being capable of shattering mountains, lifting and using buildings as weapons; extreme durability, which is also amplified by a mystical force field that grants near invulnerability. When the force field has been temporarily absorbed by Thor's Hammer, the Juggernaut's natural durability proved to be sufficient to exchange blows with Thor. The Juggernaut is described as physically unstoppable once in motion, does not tire from physical activity and is able to survive without food, water or oxygen.
The character, however, is vulnerable to mental attacks, such as psionics from beings like Jean Grey or Charles Xavior and magic from beings like Dr. Strange, a weakness that has been exploited via the removal of his helmet. The Juggernaut has circumvented this weakness by on occasion wearing a metal skullcap inside his main helmet. If the Juggernaut loses his helmet he can recreate it by touching certain materials (as long as he possesses the full power of the gem). Aside from magic, Dr. Strange can also counter the Juggernaut with the Crimson Bands of Cyttorak which, as their name implies, draw their power from the same entity who gives Juggernaut his power. It is possible for an opponent with sufficient physical strength of their own to turn the Juggernaut's irresistibility against him, by redirecting his motion so he gets stranded in a position in which he has no purchase; both the Hulk and his son, Skaar, have managed this feat. Once, the entity Onslaught, which possessed unknowable psionic and reality-warping powers, somehow ripped the Crimson Gem out of the Juggernaut, subsequently trapping him inside.
"Nothing can stop The Juggernaut!"
- Earthquake: The Juggernaut slams the ground in front of him with both fists, creating a shockwave that tears up the earth in front of him. Its range can be extended if utilized with a heavy punch.
- Juggernaut Punch: The Juggernaut slams a single fist straight down in front of him, generating a huge smash hit that sends the target flying. It can perform a dash if utilized with a heavy punch, like a mini Head Crush.
- Juggernaut Body Splash: The Juggernaut leaps into the air and lands full force on the target with his entire body weight. Its range can also be increased, if used with a heavy kick.
- Cyttorak Power-Up: The Juggernaut enters a brief pose and starts flashing. His next attack will do more damage, but it's only good for one move, regardless if it hits or misses.
- Nail Slam: Juggernaut grabs the opponent, bashes 3 times with his head like hammering a nail and lands an uppecut after. A close range throw move in X-Men vs. Street Fighter but was later removed in Marvel vs. Capcom 2.
|α||Ground||Earthquake Punch||Earthquake Punch||Head Crush|
|β||Dash||Juggernaut Punch||Juggernaut Punch||Head Crush|
|γ||Variety||Body Slam||Body Slam||Head Crush|
- Juggernaut Head Crush (Level 1): When executed, the Juggernaut dashes towards the opponent and drives his head into them with a large head charging tackle. It typically hits four to six times, but it has a maximum of 8 hits, if the opponent is in mid air regular jump and a direct hit from Juggernaut's head.
- The Juggernaut´s ending in X-Men vs. Street Fighter shows him talking to the nearly unconscious Apocalypse, saying that Apocalypse is nothing compared to him and starting to talk about the time he defeated the Hulk by outsmarting him.
- The Juggernaut's ending in Marvel Super Heroes shows him preparing to take the Infinite Gauntlet from the defeated Thanos, muttering threats towards his half-brother to himself. Before he can grab the gauntlet, Adam Warlock takes it, thanking the Juggernaut for stopping Thanos, but then warning that it's power was not meant to be used by someone like him. Adam then sends the Juggernaut back to Earth with the gem's power.