First you must buy the ds and purchase pokemon Dimond or Pearl or Platinum. Then look up on the internet how to get uxie Mesprit and Azelf. Then get that far into the game to catch them, then catch them, and trade them over to your other ds or dsi and then poofapalooza you've got yourself an azelf, Mesprit, and Uxie! My favorite is Uxie.