And he’s not wrong that Nightmare would likely require plenty of voice over work paired with CGI. In the comics, Nightmare, who also happens to be one of Doctor Strange’s earliest villains, is a Fear Lord and ruler of the Dream Dimension. He torments people in their dreams and, in order to become more powerful, he draws psychic energy from it as well.
Article source: https://www.cinemablend.com/news/2552114/one-spider-man-actor-would-love-to-play-a-villain-in-doctor-strange-2