The phrase "beloved superheroes" refers to fictional characters with extraordinary powers or abilities who are loved and admired by many people. Full definition
They aren't just fighting because someone thought it would be cool to see beloved superheroes fight; they're fighting because there is a carefully - constructed story requiring them to. (aisleseat.com)
The marketing hook is exactly the same: Watch two beloved superheroes fight it out! (pitch.com)
«Stay off the Internet,» he advised to other actors who take on beloved superhero roles. (etonline.com)