Source: marvel.wikia.com
8. Diablo
The Fantastic Four were great because they sometimes fought ninth-century alchemists.
Esteban Corazon de Ablo was one of those guys. He loved alchemy and used it to achieve immortality. And by used alchemy to achieve immortality I really meant gave up on the alchemy thing pretty quickly, and just literally made a deal with the devil. What a shortcut, Diablo.
He eventually encountered the Fantastic Four in his Transylvanian castle, so I might have been underestimating Diablo this whole time. Having a castle in Transylvania indicates a bold new level of Super villain that few people aspire to. Also, he had the all-time silliest costume, and it was really great.
Plus, he had a wonderfully supervillainous mustache.

