Scorpion Sentinel

Two mana buys a stubborn early blocker: four toughness that stonewalls a two-power attacker without trading and asks nothing of you while you dig toward the real plan. The seven-lands clause is where the same permanent switches roles. Hit that land count and the body swings for four with every point of its toughness intact, so the card that stalled the opening turns into a clock without a second draw spent. Seven is a deliberate number: it is roughly the point where a slow, controlling deck has stopped needing bodies to block and started needing bodies to close, and this creature covers both halves of that arc by itself. What the design pays for is patience. Draw it late and the +3/+0 comes online at once, but the four-toughness wall underneath is answering a threat you have already survived; the payoff and the insurance no longer overlap. This is the old blue problem of a permanent that wants to live through the early turns and cash out later, resolved in a single card that only asks for time in return.