Eldrazi Tron is built around Consign to Memory's two best targets: it counters the cast trigger on Thought-Knot Seer's discard and Devourer of Destiny's exile trigger, and shuts off colorless Kozilek's Command before it can bounce your board or exile a threat. Because their whole gameplan revolves around Karn, the Great Creator locking down artifacts and colorless value creatures, Emperor of Bones gives you graveyard hate plus a recursive body to keep pace on board. Teferi's bounce mode is a poor match for a deck full of colorless permanents like Mind Stone and Expedition Map that just get replayed, so it and some lands make room for the extra interaction. Save Fatal Push and Solitude for Thought-Knot Seer to protect your hand before it strips your best spell.