Eldrazi Tron's Urza's Tower/Mine/Power Plant package taps for huge amounts of colorless mana, and Damping Sphere caps each of those lands at producing only 1 mana, crippling their ability to cast Karn, the Great Creator or Ugin, Eye of the Storms on curve. Disruptor Flute can be named on Karn to tax it further, and Surgical Extraction can strip a copy of Expedition Map after it's used. Dauthi Voidwalker cannot block against a deck full of 6/6 and bigger bodies and dies easily to Dismember, while Sorin of House Markov and the extra March of Wretched Sorrow are too slow against their ramp into Emrakul or Ugin. Keep Thoughtseize maximized to strip Karn and Inquisition of Kozilek to strip Expedition Map before they resolve.