Unlock the Red Alloy Trophy by defeating 5 enemies in Cruel Brawl. Getting any KO's in Cruel Brawl is basically impossible if you fight valiantly, but if you are willing to be cheap, it's not that difficult. For example, I unlocked the Red Alloy Trophy using Ike. I jumped off the edge of the level, and when the alloys gathered on the side to kill me, I used Ike's up-B attack over and over again. This attack does serious damage if the tip of the sword strikes the foe right after Ike throws it and before he grabs it again. So I repeatedly lobbed my swords at the enemy alloys (from a place below the level where they couldn't reach me), grabbed the edge of the level as they reeled from my attack, and cliff-hung any of them that I had knocked over the edge or that had dropped down to intercept me.
Trophy type: enemy