How to Get the Other Forms of Deoxys in "Pokemon Emerald"by Alex Ramirez ; Updated September 22, 2017
Items you will need
2 Game Boy Advance handheld consoles
Game Boy Advance Link Cable
Deoxys is a legendary Pokemon in "Pokemon Emerald" that can be very difficult to find. Once a trainer has captured Deoxys, he will be in a default form: Speed Deoxys. However, Deoxys has three other forms: Normal Deoxys, Attack Deoxys, and Defense Deoxys. These forms can only be accessed by trading the legendary Pokemon to a separate Game Boy Advance console.
Attach a Game Boy Advance Link Cable to two Game Boy Advance consoles.
Start "Pokemon Emerald" on both handhelds.
Go to the second floor of the "PokeCenter" in any city. The lady on the far right of the room allows users to trade Pokemon between the two games.
Talk to the lady behind the counter on the far right of the room. A new menu will appear.
Select "Trade Pokemon" from the list of available options. The Pokemon in your inventory will appear.
Select Deoxys to trade the Pokemon to the handheld connected with the Link Cable. Once traded, the Deoxys will change forms.
Repeat these steps on the other Game Boy Advance handheld to trade the Pokemon back to the original trainer. The Deoxys will keep the new form it changed to when it was originally traded.