Adam I is probably some kind of cosmic version of Superman. And vice versa. He has lived for billions of years, and was the sole protector of Wonderworld (a mysterious location that is somewhere in the DC-universe) for billions of years, before he found other individuals like himself, to protect it.
He met Aquaman, Kyle Rayner and Wally West once. One of his teams members helped them to get back to Earth. After they had gone, the team continued to await the arrival of a massive threat that can destroy universes.
When Metron pays them a visit after billions of years, they`re still waiting, still resting and preparing. How long they shall wait?