Checkpoint Officer

A tapper is the oldest defensive engine white has: a body that never really blocks, never attacks, and instead spends mana to keep the scariest thing on the far side of the board out of the game. The activation cost here does all the balancing. Icy Manipulator and its descendants tap for a single generic mana; this one demands white plus a generic every turn, which slows the loop enough that it cannot casually neutralize an attacker and still leave you resources for anything else. What it buys in exchange is a form of repeatability removal cannot match: nothing dies, nothing gets exiled, the same creature simply misses combat as long as you keep paying. On defense it holds off a beater one turn at a time; before your own attack step it functions as pseudo-removal, tapping the sole blocker so a real threat gets through. The 1/2 frame is deliberately unthreatening, because a tapper's value is in surviving to activate, not in the stats printed on it. This is a role-filler in the truest sense: a common-rarity control lever for grindy white decks that want to answer the biggest creature over and over without committing a card to killing it.