Amulet Titan needs Amulet of Vigor plus a bounce land or bounce package to enable a fast Primeval Titan chain into Scapeshift for a haymaker turn, so Thoughtseize is excellent to strip Primeval Titan or a key enabler before they combo off. Celestial Purge is a low-impact include here since almost none of their permanents are black or red — hold it as a marginal option rather than a real answer. Fatal Push struggles against Primeval Titan's mana value, so trim one for the proactive disruption, and Chthonian Nightmare is too slow and reactive against a deck that wins on a single big turn. Prioritize disrupting their bounce-land engine over trying to race.