You can't trade over wifi. The only options are:
Play with Friends(A.K.A Battle over Wifi)
Match with Friends(Self-Explanitory)
Match Randomly(This is cool, you just choose this option, and wait for somebody to come on and then you match with them, heck thats how I got a Chiccimon with 67 Aptitude at LV.1!)
I still WANT the Ultimate Sword, just for my Apollomon. If you think you can beat me, lets battle.
EDIT: To add friend codes to to Nintendo Wi-Fi connection on the main menu, and then Add Friend Code, and finally, Enter Friend Code.
« Last edited by Shadow Entei on Nov 27th 2007 »