Lifegain grinds out incremental advantage through Amalia Benavides Aguirre's explore triggers and Liliana the Faultless, so Duress proactively strips their noncreature payoffs and answers, such as Ajani Resolute, Lunar Convocation, Case of the Uneaten Feast, or Erode, before they take over the game. Strategic Betrayal makes them exile a creature of their choice along with their graveyard, cutting off the creature targets for recursion from cards like Moseo, Vein's New Dean. A third Requiting Hex (Instant) cheaply answers their many low-cost creatures like Hinterland Sanctifier and Enlightened Confidant, and can gain 2 life if you pay the optional blight cost. Chandra, Dispelling Exhale, and Three Steps Ahead are too reactive and slow against this proactive value engine, so trim them for discard and removal.