Hard Jack

Jack lives a normal life in a declining world only to awakened after his death. Others of the dead convince him that he could have done better and may even save the world from the impending doom that claimed his life.
Jack agrees to try and returns to the world armed with a few friends and a few tools of very advanced design. He must, however, work with the world to change it. He knows that he can not exhibit a few miracles and expect the entire world to follow his lead.
His team builds their power through the usual means and turns their abilities outward to discover the local abode of the creator. They have surmised, with a little inside information, that the human race was created by an AI for a specific mission. They plan to make contact and the convince the entity to advance humanity beyond the nuclear armaments that would destroy it.