I think it would be very sad to talk about the end game 1 week after the launch of the first .EN world. But everything happens once, so: If a world reaches certain amount of points, the endgame starts. Endgame is not in connection with closure, so if somebody wins the title 'Eternal King', the world will be still available to play. Good to know that every kingdom will have it's king, so several endgames can be in progress at the same time. That is what I know about it, and I'm sure that the wiki will be updated to the latest news.