Earth-770

Earth-770 is the world where Leon and Paris are sent at the end of Book 6. The world is identical to Earth-185, however, Ashton had never lost his parents. He had made it to the Ariean Tribe due to exploring on his own, where he met the Faron Burke on this world, unrelated to his family. The two would start a family, creating two new members of the Mayflower family. Earth-770 is now a wasteland, an empty planet with no biological life remaining, buildings and structures have collapsed, leaving nothing but destruction behind. 
Ashton's insanity in Earth-185 was the cause of Leon's creation, hence why he doesn't exist in Earth-770. Without Leon, Paris would never be freed, therefore he doesn't exist either.