Every human has flaws, and superheroes are no exception, especially those in Justice League. Along with unique powers and skills, they also have their weaknesses. Now, thanks to the cast members, we now have a clearer idea of what these comic book characters will be struggling with inside their hearts as they face off against Steppenwolf and his army of Parademons.
Wonder Woman is hundreds, if not thousands, of years old, making her the eldest Justice League member. Gal Gadot told SFX Magazine (via ScreenRant) that the Amazon's painful experiences (losing her beloved aunt Antiope and her lover Steve Trevor) actually weakened her to a certain extent:
Wonder Woman is 900 or 3,000 years old – depending on who you listen to – and because of that, she's very lonely. She's had a lot of loss throughout the years.
Ben Affleck said that Batman may not be as old as Gadot's character, but he’s dealt with losses in his life. Those losses created a certain amount of darkness and cynicism within that would affect his interactions with others:
Bruce Wayne has a kind of inner darkness and cynicism that he has to get past in order to bring his team together.
The Flash is younger than both Wonder Woman and Batman; he's actually much younger than we initially thought. So, the things that bother him are different and clearly not that grave. Here's Ezra Miller’s take on the Scarlet Speedster:
Barry despises social mores and time-consuming bureaucracies.
Cyborg is one of the younger Justice League members, but we recently learned from Ray Fisher that his struggles are very unique:
One of Cyborg's strengths is also his weakness, in that he is extremely sensitive to the world around him. We see a lot of interaction and a lot of growth within the character. His need to be understood by the people that are closest to him, is tough, particularly with his father, and just being able to open up to the world around him is very difficult.
The half-human, half-Atlantean Aquaman (Jason Momoa) is more powerful than a regular human, or even a regular Atlantean, but he doesn't quite know what to do with these powers:
He doesn't believe in himself; he doesn't know what to do with the powers he has. He's going through tons of loss. He hates Atlanteans. The fact that people are calling him Aquaman right now - he couldn't give two sh*ts about anything Atlantean. So he's really not quite there yet.