Insanity gets a bad rap. The “Unraveling Mind” deck is built to take advantage of the Madness ability. When you discard a card with Madness, you can play it—usually for a discount, and at a time your opponent won't expect. Discard Reckless Wurm to pay for Lightning Axe, for example, and you can take out almost any opposing creature and get a surprise blocker into play at the same time.