After seeing his parents murdered, billionaire Bruce Wayne dedicated his life to becoming the greatest detective in the history of mankind. He has encountered Constantine on just a couple of occasions - first during the Crisis on Infinite Earths, when they met by chance in a street (Swamp Thing volume 2 issue 44 and then when Constantine sought his help to track down a deranged Swamp Thing (The Search for Swamp Thing issue one. Batman dislikes Constantine's attitude, but will begrudgingly work with him if he has to.
First appearance: Detective Comics issue 27
The last son of Krypton, Kal-El was sent to Earth by his parents to escape the destruction of their planet. There, he was raised by a kindly Kansas couple and became Superman, the greatest superhero of them all. Constantine sought his help to track down a deranged Swamp Thing (The Search for Swamp Thing issue two. Constantine's lack of interest in helping people in trouble unless it benefits him puts Superman's back up somewhat.
First appearance: Action Comics issue 1