During Cruel Melee, to get easy KOs against the wire frames, choose Roy and jump off the edge (stay in jumping range of the platform as you will need to get back on). Now, listen carefully. If this maneuver is done correctly, the foes should crowd around the edge. Now, use Roy's blazer attack (B+up). For some reason, the foes go flying up into the air really high, usually killing them. This helps to get the Mr. Resetti trophy. I have gotten 10 KOs in Cruel Melee!