In Marvel Comics, the Juggernaut is Cain Marko, the stepbrother of Professor X. Unlike most X-Men characters, he is not a mutant; his powers are mystical, granted by the found in a hidden temple during the Korean War.

His primary vulnerability is mental attacks. This is why he wears a signature heavy helmet to shield his mind from telepaths like Charles Xavier.

In recent 2020s storylines, Cain has transitioned from a villain to a legitimate hero, even becoming a member of the X-Men . Gaming: Tactical Streaks and Hero Blades