According to ancient records from Kamar-Taj, Hell was a bizarre dimension attached to the material world, filled with scorching lava and the heavy stench of sulfur. It was a barren wasteland where not a blade of grass could grow, with nothing but hard, dry, cracked earth and thick clouds that never dispersed.
Mephisto was one of Hell's rulers. He had always enjoyed taking human form to roam the material world, tempting others, toying with souls, and deriving endless pleasure from it.
The Hell Lord never tired of this vile hobby. The widely known tale of "Faust" had been based on him.
Unfortunately, after Agamotto established the Three Sanctums, refined the magical system, and organized sorcerers to purge inhuman creatures, his successor, the Ancient One, used thunderous methods to drive out every creature from beyond the material world!
Because of this, Mephisto had clashed with both generations of Sorcerer Supreme. He had even rallied the denizens of Hell into a vast dark army, attempting to invade the material world on a grand scale and claim it for himself.
The first time, Hell's seven great rulers had emerged in full force, leading countless Dark Creatures such as Skeleton Demons, Flame Demons, nightmares, Stone Golems...
The newly established Three Sanctums had likewise gathered the Knights Templar, the Hermetic Order, and many other forces to resist the furious onslaught of the dark tide. That war had not been recorded in history, yet it had truly been a crucial battle concerning humanity's survival, its brutality beyond imagination.
In the end, under the leadership of the previous Sorcerer Supreme, Agamotto, the Three Sanctums had won a difficult victory, keeping Hell's seven rulers and their dark legions beyond the material world.
The second time, Mephisto used the Spirit of Vengeance to select Ghost Riders in the material