Theo would fall into his place in a Superverse pretty much by accident. His parents, and later friends who cared about him, would have tried to contain that 'something different' about him ever since he could remember. One day, soon after switching medicines and before the new one had fully kicked in, Theo would have discovered that something different about himself completely by chance. For reasons known only to him, if he even understood them, he chose to interrupt a mugging. Realizing that people got very, very disoriented and disorganized around him when he chose to exert a little effort would have sent him on a quest to find out more about what all the medicine has been for, a quest that ultimately leads to him embracing his own strangeness.
He would be the ultimate unaffiliated. In fact, I'd have to call him a true neutral (oh yes I am bringing D&D into your Marvel/DC world) - he isn't going to go out of his way to help people, but he doesn't want to hurt anyone, either. His behavior is too chaotic to be considered lawful, but the guidelines that govern his speech patterns are too rigid to be considered chaotic. He would sometimes pop up on the hero's side, and sometimes on the villain's, depending on the weather - it's as good as any other explanation for why he does what he does.