Sorceress of Burning Spires

{x}{b}{r}{g}, {t}, Discard a card: Sorceress of Burning Spires deals X damage to target player or planeswalker and each creature that player or planeswalker's controller controls. Activate this ability only any time you could cast a sorcery.
Substantiate —Whenever Sorceress of Burning Spires becomes tapped, if it's not attacking, you may discard a card. If you don't, it deals 3 damage to you.