Ulamog's Nullifier

The counterspell is fenced behind a specific tax: you have to send exactly two cards owned by your opponents from exile into their graveyards, and if you cannot pay in full, the Cancel simply does not fire. That makes the card a referendum on the Processor archetype's core problem. Processors were designed to be dead weight without an ingest engine feeding cards into exile ahead of them, so their payoffs were gated behind an entire subtheme's worth of setup. Here that setup buys a hard counter, which is a real reward, but only if the graveyard-feeding shell has done its job first. Without two exiled cards to spend, this resolves as a 2/3 flash flyer and nothing more: a serviceable ambush blocker or evasive body, but no counter attached. That fallback is what keeps the card from rotting in hand the way a purely reactive spell can; flash and flying mean it is always at least a creature you can hold up at instant speed. Devoid does the connective work, marking it colorless Eldrazi while leaving it castable on an ordinary blue-black mana base, which was the whole faction conceit: monsters from beyond color, paid for with normal lands. The card rewards you for building the exile engine, then hands you the counterspell as the payoff for having built it, rather than defaulting the effect into your hand for free.