Go to the battle Tower to clone Pokemon (and items!) in Emerald, do this:


1. Equip the Pokemon with the item you want to clone;
2. Put that Pokemon in a box, doesn't matter which one;
3. Save;
4. Withdraw the Pokemon from the box;
5. Talk to the lady on the far right and agree to do the challenge;
6. Say Yes to the need to save the game;
Now, you have to wait a second before it gives the saving prompt.
7. Do NOT Save, instead, reset (soft and hard both work) the game;
8. When you turn on the game, you'll have the Pokemon in your team and in the box (with the item).

You can clone up to six Pokemon per time