Long in short of it, a young boy was sent to another world by a magic portal, then he'd continue to follow that portal but each time he went through it just sends him to one world to another; since then he was granted the powers of a sorcerer, then became a ringwraith, serving a dark lord then became a good guy and started a new career as a superhero. (somewhat similar to the Robot "Peace" from Ralph Bakshi's Wizards)
I still don't have a definite origin to this character!
Originally his parents were part of an espionage and were shot down when he was a baby, he was then taken and raised by a circus ringleader only to be separated by his foster father years later after a government mishap. (inspired by Cesar's origins in the original Planet of the Apes films)
That's just one of a couple origins I thought, but either way how he got his powers are pretty much the same formula as I wrote above. I'm not really all too satisfied with