Bought Black 2, beat the E4 quite a while ago, but started hunting for legendaries, catching other strong Pokemon, exploring the post-game a little while ago, and I like how much there's still left to do in the game. And it's just taunting me with the challenge mode, since I don't want to leave everything behind, but I really wanna try it with increased difficulty. I decided I'm gonna beat, explore and catch anything major first, trade it all over to a friend, and then start over in challenge mode then. I also really want all the keys, however I don't own White 2, nor do I know anyone who does.