Why is Juggernaut so powerful?

Why is Juggernaut so powerful? Charles followed Cain into a cave that housed the lost temple of Cyttorak, a powerful mystical entity. Therein, Cain unearthed the Crimson Gem of Cyttorak and, upon touching it, was transformed by its mystical energies into a human juggernaut.

Charles followed Cain into a cave that housed the lost temple of Cyttorak, a powerful mystical entity. Therein, Cain unearthed the Crimson Gem of Cyttorak and, upon touching it, was transformed by its mystical energies into a human juggernaut.