Esteban Corazón de Ablo, aka Diablo is a villainous alchemist and enemy of the Fantastic Four. He was introduced 60 years ago in Fantastic Four #30 (September 1964) as a creation of Stan Lee and Jack Kirby.
Esteban was originally an alchemist working in Saragossa in the 9th century when he sold his soul to Mephisto to increase his life span. Years later, he relocated to Transylvania and made a pact with vampires. When the villagers grew tired of his antics, they formed a mob and buried him in a crypt under his castle.
Flash forward to the 20th century, when the Fantastic Four visited Transylvania, a local named Baron Hugo told them about Diablo. The alchemist whispered to Thing to free him from the crypt, promising to give Thing a potion that would turn him halfway human. He then told Thing that if the superhero worked for him for a year, Diablo would give him another potion that would make him completely human. When the rest of the Fantastic Four found Ben working with Diablo, they tried to stop him, but were unsuccessful.
Diablo reentered society by selling his chemical compositions to the world market and he became a very, very wealthy man. Mister Fantastic researched Diablo’s chemicals and discovered that they only worked for a short time before failing. Now a societal pariah, Diablo started planning to use his alchemic abilities and loyal followers to conquer the world.
The potion he had given the Thing wore off, so he turned on Diablo, who retaliated by putting Ben in an unbreakable cage. The rest of the Fantastic Four tried to rescue him at Diablo’s fortress, but the alchemist disabled them with chemical pellets. While he sequestered the rest of the team in capsules, Thing broke out of his and chased Diablo through his castle.
Thing pursued Diablo back to the crypt where the alchemist was originally imprisoned. Before he could get back out, Thing put the giant stone that had blocked the exit back in place. Anger got the better of Ben, and he smashed the stone in its position, causing damage to the rest of the castle. As the building began to crumble, the Human Torch melted the stone slag to further reenforce Diablo’s prison.
Refusing to give up, Diablo created a potion with the materials available inside his stone prison. He melted the surroundings, escaped, and swore to get revenge on the Fantastic Four.