Seafloor Stalker

Evasion is what this Merfolk sells, and the party count is what makes the price bearable. Paid at its floor with only itself in the party, the activation is a wince: four mana to push a 2/3 through for a single extra point of damage is a rate no evasion creature is worth. The design bet is that you never pay full price. Each of the four party slots you fill (Cleric, Rogue, Warrior, Wizard) shaves the activation down, so the same ability that reads as a four-mana indulgence on an otherwise empty board collapses to a one-mana finisher once you have assembled a full crew. That scaling is the payoff: build the roster first, and an evasion tax becomes pocket change, turning a modest body into a repeatable, near-free way to close games. Because it counts as a Rogue itself, it fills one of its own slots, a quiet self-synergy that reaches the deep discount faster than the raw count implies. The tension the design resolves is the old problem with unblockable creatures, which tend to be either cheap enough to activate that they warp games or expensive enough that nobody bothers; here the price is genuinely prohibitive until you have done the deckbuilding work party demands, at which point it flips from tax to reward.