Mercadian Masques, released on October 4, 1999, begins the Masques block with a focus on control, tempo, and resource management. The set introduces Spellshapers, creatures that turn cards into reusable spell effects, and emphasizes tribal themes with Rebels and Mercenaries. It also includes mechanics like Buyback and Free Spells. Notable cards include Rishadan Port, Misdirection, Brainstorm (reprint), and Lin Sivvi, Defiant Hero. While lower in power than previous sets, Mercadian Masques offered deep gameplay and long-term value through utility and disruption.