Created by writer Stan Lee and artist Jack Kirby, the character first appeared in Fantastic Four #30 (September 1964).

[4] Esteban Corazón de Ablo was a powerful alchemist in 9th century Saragossa, who sold his soul to the demon Mephisto to lengthen his life far beyond a human span.

Another century later, the Fantastic Four appeared in Transylvania on a vacation, when a local named Baron Hugo told them the legend of Diablo.

Diablo soon made his appearance known to the world, and sold his alchemic chemicals internationally, making him the richest man on the planet.

The world turned on Diablo, but he had already built up an army of loyal followers and was prepared to use his alchemic powers to conquer the planet.

The Thing followed behind him and reinserted the giant, stone plug, and then smashed it with both fists, causing the entire castle to come crumbling down upon the crypt.

His next move was to travel to North America and New York's State University, where he helped Professor Gregson Gilbert to animate his android creation Dragon Man.

[22] He was later seen in Vieques, an island–municipality of Puerto Rico, where he helped Spider-Man and the Human Torch defeat a giant radioactive sea monster that was devouring the residents and tourists.

[24] During the Origin of the Species storyline, Diablo is invited by Doctor Octopus to join his supervillain team, where he promises them that they will receive a reward in exchange for securing some specific items for him.

[27] Sometime later, Diablo kidnaps Maria Hill to acquire the security code clearances to all active helicarriers and the Triskelion, but is defeated by a reformed Doctor Doom operating as the Infamous Iron Man.

[30][31][32][33] Diablo is a practitioner of the alchemic sciences, based upon reconstructing molecules by mystical means, and has obtained this knowledge through study.

Diablo employs a huge arsenal of alchemical weapons that he discovered or invented, and conceals within hidden pouches and pockets in his costume.

[34] His mixtures include nerve gas pellets, freezing potions, and pills that make people susceptible to Diablo's hypnotic orders.