Alfred Pennyworth: How do you know your team's strong enough? 'Cause if you can't bring down the charging bull, then don't wave the red cape at it.
Barry Allen: This guy's probably fought hundreds of thousands of other super beings on the other planets he's destroyed, right? And we have to assume he's won.
Bruce Wayne: I don't care how many demons he's fought in how many hells. He's never fought us. Not us united.
Wonder Woman: You said the age of heroes would never come again.
Bruce Wayne: It will. It has to.
Jonathan Kent: You were sent here for a reason. And even if it takes you the rest of your life, find out what that reason is.
Answer: Martian Manhunter is played by Harry Lennix, who also plays General Swanwick, a character who appears in Man of Steel and Batman v Superman (and we can see he transforms back into Swanwick he leaves), revealing that Swanwick was Martian Manhunter the whole time, so the indication is he got to Earth before Man of Steel. He assumed Martha's identity to speak with Lois, specifically to have a heart to heart with her as she is depressed due to Clark's death. Martha is present every other time we see her, when she leaves the Kent home at the beginning and when she reunites with Clark later on. This scene was the only time Martian Manhunter used her identity.
Casual Person