Terrageddon's plan is Armageddon backed by mana-efficient threats like Terravore and manlands, so Naturalize answers their Sylvan Library, while Xantid Swarm, free via Aluren, lets us attack to shut off their Swords to Plowshares or a surprise instant on our key turn. Compost stays boarded since they run no black cards. Wall of Roots is a creature that survives Armageddon, but we trim two copies for more proactive disruption, and cut Mesmeric Fiend since their pressure comes mostly from the battlefield rather than their hand. Hold Chain of Vapor to bounce a Terravore before an Armageddon locks us out of answers.