Dean was proud of Evie for making honest guesses and thinking about them as she was given the answer to the questions. He heard Evie being curious about how to take care of demons. When Sam told her about the demon blade and showed it to her, he noticed her interest. "If you also have an angel's blade, it can also kill a demon," Dean added. "If you need to stop an angel, holy oil set ablaze can stop an angel in their tracks. If they try to go through it, they can get killed. An Angel blade on an angel can kill them too if you can get one."