Thought Shucker

Threshold has always been a payoff that arrives after the game has spent itself, and a 1/3 body is precisely the shape that survives long enough to collect on it. The design here folds a delayed engine into a defensive frame: early on it blocks small attackers and does nothing else, then, once the graveyard crosses seven cards, it converts a mana investment into a body upgrade and a card in the same activation. The "only once" clause is the restriction that keeps it modest. This is not a repeatable draw loop; it is a single late-game inflection where the card stops being a wall and becomes a 2/4 that has already replaced itself. That one-shot limit means the activation reads as a threshold-gated cantrip stapled to a blocker, not an advantage engine to build a deck around. What makes the shell coherent is the alignment of costs to the plan: a controlling, self-milling, or attrition-oriented deck naturally fills a graveyard while trading resources, and this rewards exactly that patience without ever demanding you deviate from it. The counter is doing quiet defensive work, too, lifting toughness from 3 to 4 so the card outlasts the small red and green attackers a defensive blue deck fears most. A quiet, honest common: a wall that earns a card and a bump once the game has run long enough to justify both.