In the single player Arena mode you can steal your defeated opponent's emblem. To do this you of course have to beat an opponent in the Arena, then once beaten you can go back to the opponent selection screen where everyone is ranked by number. Highlight and select someone you have defeated and then press START + SELECT and you should hear a sound. Press the two buttons again and again until you hear the sound. Once you hear the sound go to the Edit Emblem screen and the emblem selected will be the one you just took from your opponent. You can then edit it or just wear it as your own.