Amulet Titan wants to chain bounce lands and Amulet of Vigor into an early Scapeshift or Primeval Titan, so Molten Rain punishes their thin, nonbasic-heavy manabase while dealing 2 damage, and Damping Sphere causes bounce lands that tap for two or more mana to produce a single colorless mana instead. Smash to Smithereens is a clean answer to Amulet of Vigor itself while pushing damage. Chandra's Incinerator and Arena of Glory are too slow against a deck that can end the game out of nowhere once it assembles its mana engine, so cut them for the proactive land and artifact disruption.