You guys are completely invincible during this phase, and these guys are no match for you. During phases like this, you will describe slaughtering your poor weak foes in as creative a manner as possible, using whatever environmental hazards you can think of. The more elaborate your kills, the more goodies you get.
You may use your killer weapons, but in the event something rolls up that can hurt you, you might not have enough uses... And while you don't need your killer weapon to dispose of these fools, uses can be expended to make flashier, more valuable kills. You will be graded according to how fancy you are.