David Corenswet, who plays Superman, "fits the role better than any other actor since Christopher Reeve," says the author.The word “Marvel” wasn’t always followed by “Cinematic Universe”. Once upon a time, Marvel was a comic book company on the verge of bankruptcy. Then came Iron Man and a last-ditch effort to transform its remaining intellectual property into a profitable business. We all know what happened next — the Avengers, a Disney buyout, massive profits, superhero fatigue —  but even in that very first movie, the seeds of a sprawling, 36-film saga were already being planted.Superman needs to accomplish something similar. The first movie in director James Gunn’s new DC Universe (a sparkling clean slate to replace the dour DC Ex