New Delhi, Oct. 24 -- Robert Downey Jr is returning to the Marvel Cinematic Universe, but this time he will not try to build a suit of armour around the world. In Avengers: Doomsday, the actor will take on the role of one of Marvel's most formidable villains - Doctor Doom. But who is that exactly?

The casting of RDJ raised questions about the character's comic book origins, his complicated history with the Fantastic Four and what his arrival could possibly mean for the Avengers.

Created by writer Stan Lee and artist Jack Kirby, Doctor Doom made his first ever comic book appearance in Fantastic Four #5 in 1962. He is the ruler of Latveria, a fictional European nation, and combines scientific genius with mastery of sorcery. That combinati...