Both of Orm's parents were Atlantean. Presumably his dead dad (Marius? I think?) is still in his respective tomb.
Nothing compares to Reis. It's like the curse of the Aqua-books. It was my belief when Pelletier was coming on board that they should've tried something different and slightly more stylish, but he's been doing work with the established style. Parker's stories could use a dose of ambient mood-building, though. I don't think they need to "breathe" quite as much as Johns mega-decompression but some establishing stuff where you like, follow a camera that sinks to the sea-bottom in the opening pages, or something. A mysterious zoom into a cave. An exploration of the ocean floor.
But the ideas for Atlantis themselves Parker has been laying down are all gold.