Eldrazi Ramp aims to use Utopia Sprawl and Sowing Mycospawn to accelerate into game-ending threats like Emrakul, the Promised End and Ugin, Eye of the Storms well ahead of schedule, so your primary goal is to combo off before they stabilize. Harbinger of the Seas enters to punish their Stomping Ground fetches and Forest-based Sprawl ramp, meaningfully slowing their clock without costing you a counterspell. Post-board they will introduce Trinisphere and Vexing Bauble to tax Disrupting Shoal and Force of Negation, making Engineered Explosives critical — resolve it at X=3 to clear Trinisphere before going for Charbelcher. Consign to Memory is the key innovation here: even if Emrakul is cast through Cavern of Souls making it uncounterable, its triggered ability (granting them control of your next turn) is a separate trigger that Consign to Memory can answer, letting you survive the resolution. Commandeer gives you a last-resort option to steal Emrakul or Ugin off their own stack, converting their best threat into your win condition at instant speed.