Kevin Feige is the madman/genius that made Marvel’s Cinematic Universe/Phase 1/Avengers franchise from the Marvel Comics to the theatrical screens. He provided his advice to Warner Bros regarding their efforts for a similar/parallel Justice League film series.
“I’m sure they have smart people over there who have a plan and know what they’re doing. Man of Steel looks like it’s going to be awesome and obviously Dark Knight is awesome. I don’t know,” Feige told Collider when asked about Warner Bros.’ troubles with Justice League. “It’s what I say all the time and have said over the years, which is, have confidence in the characters, believe in the source material, don’t be afraid to stay true to all of the elements of the characters no matter how seemingly silly or crazy they are.”… Feige also acknowledged that the idea of bringing preexisting characters together to form a superhero team came from Justice League originally. As he said, “Justice League was first.”
“I think there have been a lot of great DC stories and there are a lot of great DC characters, and if they focus on those things the audience will be interested,” Feige said. “It was a very unique model that we were lucky enough to be able to do — introducing each individual hero before introducing The Avengers. That, to me, is what was always interesting about The Avengers. … The Avengers was cool because they were preexisting characters that teamed up for a big event. I think that’s why Justice League was cool, Justice League was first. That’s what they did first in comic form.”
That all sounds correct.