If you read Captain Atom, you can obviously notice the connection to Doctor Manhattan in the character. Not so much in the personality, but rather the powers he possesses. And then of course, there are the little nods - the glass desert in Issue #3, the image of the giant Captain Atom in Issue #5.
But, in developing the book, I found myself thinking about Superman quite a bit in determining how Captain Atom would be in this incarnation. Guess you could say it was all priming me for Superman Beyond. It all boiled down to making Captain Atom a polar opposite to Superman. Nathaniel was an Air Force pilot, a human being dedicating his life to fighting for his nation. In becoming Captain Atom though, his place in the world becomes much more alienated. He's considered a threat - and his incredible powers are classified more as dangerous than wonderful. Contrast that with Superman, who is an actual alien living among us humans on Earth. We embrace Superman because he looks like one of us. His powers are seen as wondrous and appealing, and we come to see the best of ourselves in him - not only in terms of physical potential, but also moral fiber. But isn't Captain Atom just as honorable? Just as heroic? Yes, he is. Unfortunately, his powers only serve to isolate him more and more from humanity. In the people's mind, he is the alien - An opinion that affects Captain Atom as he begins to see himself as being other than human. It comes down to each character's place in the world.
This brings me to Superman Beyond, where that notion of having a place in the world is a central theme. In our timeline, Superman is firmly grounded on Earth. It is his home. He has family and friends and loved ones. His existence as Clark Kent keeps him connected to humanity. But can the same be said twenty years down the road? When those personal connections are dead and gone, what will keep Superman in touch with humanity? Where does he fit in, if anywhere? Look at the costume he wears, which highlights his Kryptonian heritage.
Is this the beginning of Kal-El pulling away from Earth altogether?