Scoot McNairy who was spotted at the cast of [Batman v. Superman: Dawn of Justice](movie:711870), back in june 2014 commented on USA Today about his upcoming role:
“It’s definitely 100% a character I’ve never played and I can’t speak too freely on it, but yeah, getting into that thing was definitely something I had to wrap my head around emotionally in order to play that character. But with that being said, I had a lot of fun doing it when I was in the process of shooting on it — my head was in a different place but I’m really excited to see how it turns out and what they do with it and see the film.”
Now, assuming that the name of the character remains a mystery we still don't know anything, but it also helps us fans to narrow our speculation.
I don't really think he is the guy McNairy would wrap his head emotionally to play, as he is a reporter/photographer with no actual powers and mainly serves his role as Superman's supporter.
This character is probably an easy target since he is absolutely related to batman and superman, but he is probably gonna make his first appearance in the [Justice League Part One](movie:401267).
He is a speculated character who can bring a whole new story in Batman vs Superman, if we can tell by his comic book history and his relation with metal men and science squad.
Well, if you didn't consider the socks as part of the characters outfit, but as something that can later edited into bionic legs then you have probably thought about Metallo. He is one of superman's nemesis who gets energy from green kryptonites and that makes him one of the few characters that can actually kill him. So, if what McNairy meant when he said "wrap my head emotionally" and "something that he has never done before" is playing a supervillain then i think that's the most possible way to go.
You can never be sure when you are listening to fan theories and speculation. So, could he play someone who haven't been mentioned before, like enigma?
Or someone weirdly speculated like ted kord?
Let me know what you think.