Merfolk Cave-Diver

A 2/4 for three mana that blocks all day is not, on paper, a threat, and that inversion is the whole trick: this Scout is a wall that turns into a spear the instant any creature you control explores. The trigger keys off the whole board, not just itself, so a turn with several explorers doesn't just draw cards and sort the deck, it stacks power boosts and re-confirms the can't-be-blocked clause with each additional explore. That converts the mechanic's usual role (a little incidental value on the way down) into a combat-math engine, where a wide explore turn pushes real damage through a board that should have been able to hold. The base rate is deliberately unthreatening on offense; the design gates the payoff behind commitment to the explore theme, so this card is a blocker until the deck around it decides otherwise. Feed it a chain of triggers and the defensive stat line becomes the finisher those triggers were quietly building toward.