Zarathos

Zarathos is a demonic being who tortures and devours souls. As explained in Ghost Rider #77 (1973 series), he had slumbered beneath the earth for eons until summoned by a sorcerer. Zarathos was offered a steady supply of souls to consume in exchange for his aid in vanquishing enemies of the sorcerer's tribe. The alliance flourished and a strong cult built up around Zarathos - this got the attention of Mephisto, who soon decided that Zarathos had too much of a following and was depriving him of souls. Mephisto eventually confronted Zarathos & defeated him.

Zarathos was forced to serve Mephisto in the Netherworld, though still was powerful enough to avoid total confinement. Mephisto would send his unruly vassal back to Earth on occasion, binding him to human hosts and allowing him to ravage souls - in smaller fashion, of course. In time, one of these human hosts would be Johnny Blaze.