Waverider is the first "new" character DC introduced to me. It was my first DC crossover, where the future is ruled by a mysterious hero gone rogue and taken over. Bouncing from hero to hero trying to learn who the real villain was. After teaming with the other heroes, Waverider then became a another member of the Linear Men. He may not be too obscure, but most don't recall this time traveler. To learn more about him, check out this link.