"Duh! So, we're asking you now, what are some of your favorite lines that this warlock brain produced?"

Charlie Sheen is asking the audience to share some of their preferred lines from the warlock brain. He is indicating that the warlock brain has actually produced some excellent lines and he wants to know what the audience thinks are the very best ones. He is likewise being sarcastic with his use of the expression "Duh!" which indicates that the audience must already know what he is asking. He is likely trying to get the audience to participate in a discussion about the warlock brain and its lines. He is likewise most likely trying to get the audience to think of the warlock brain and its lines in a more creative way. By asking the audience to share their favorite lines, he is motivating them to think about the warlock brain in a more significant way. In General, Charlie Sheen is trying to get the audience to engage in a conversation about the warlock brain and its lines in a more imaginative and significant way.