|Real Name||Cain Marko|
|Alternate Identity||(Unstoppable) Juggernaut|
|Powers and Abilities||Superhuman Strength and Durability|
|Family and Friends||Charles Xavier (Half-brother)|
Juggernaut was Xavier's half-brother who had powers granted by unknown mystic means. At some point, he had been defeated by Xavier and incarcerated in a high-security prison under the supervision of Captain Stone. He was permanently sedated to prevent him from ever breaking out. However, he was discovered by Mystique and broke him out. She sent him after his brother so she could steal Cerebro. He ignored Mystique's request, seemingly betraying her, so she then turned against him. He was then defeated by a combination of Xavier's X-Men, Mystique's Brotherhood of Mutants, and the Xavier Mansion's Danger Room. He was returned to his cell.
Mystique later used the threat of Cain's escape to draw Xavier away from his X-Men. Charles had to be at the prison to keep Juggernaut unconscious while his cell was repaired. He did not escape but Charles did realize Mystique's plan.
Mystique once again released him and replaced him with Charles. He went on a rampage forcing the X-Men to fight him atop a dam. Cyclops defeated him when eh unleashed the full force of his optic blast against him while Rogue used her powers to steal his. She used his own strength to throw him into the air so that Iceman could freeze him in a block of ice.
Powers and Abilities
Juggernaut was voiced by Paul Dobson.
In the Comics
Juggernaut's powers are due to the Crimson Gem of Cyttorak, though no specific connection is made in the series.
Charles Xavier is his step-brother rather than half.
Juggernaut has actually joined the X-Men.