World Domination Achievement
You want to join the 7th Column?This is a viral achievement. One person started with it and it has spread from there. To get it you must kill someone who has the achievement. Just play some Xbox Live games and you'll get it. You don't have to win. You'll get the achievement in the post-game lobby. If you're in a hurry, you can also check out the achievement trading thread HERE to try and find someone who will let you kill them, so you can get the achievement.