Eldrazi Tron depends entirely on its Urza's Tron lands plus Eldrazi Temple and Ugin's Labyrinth to cast giant colorless spells, so a second Blood Moon turning those into Mountains is devastating and often strands them off colorless mana entirely. Damping Sphere caps mana produced from tapping two or more mana sources, directly hurting their Tron bonus mana output, while also taxing them if they chain multiple cheap artifacts like Expedition Map and Talisman of Resilience. The Legend of Roku is too slow and card-disadvantage-prone against a deck that can deploy Karn, the Great Creator or Ugin, Eye of the Storms ahead of our development. Thraben Charm's creature-damage mode is weak against their big, tough Eldrazi bodies, so we favor the land-disruption plan instead.